Which day between June 4 and August 12, 2026, will see the highest US airline passenger volume?

• My median prediction for the day with the highest US airline passenger volume starting June 4, 2026, is 5th July 2026.
• This date is the Sunday following Independence Day (Saturday, 4th July), which coincides with the massive return travel demand from the U.S. Semiquincentennial (250th anniversary) celebrations.
• Historical TSA data shows a nearly perfect correlation between summer volume peaks and Sundays, with 2024 and 2025 peaks occurring on the Sundays of late June or early July.
• The 2026 FIFA World Cup (ending 19th July) will provide a high volume floor throughout the summer, but is unlikely to surpass the domestic holiday-return peak.
• Airline financial data and earnings calls from Q1 2026 confirm that carriers are preparing for record-breaking summer demand despite rising fuel costs and capacity constraints.
• Other secondary candidates for the peak include Sunday, 21st June (post-Juneteenth) and Sunday, 19th July (World Cup Final).

Key figures

Historical context

The TSA checkpoint travel numbers serve as a high-frequency indicator of US air travel demand. Historical data shows that single-day records are almost exclusively set on Sundays during peak summer or holiday periods. For example, the all-time TSA record of 3,134,613 passengers was set on Sunday, 30th November 2025 (the Sunday after Thanksgiving). Within the summer window, the 2025 peak was 3,096,797 on Sunday, 22nd June, while the 2024 peak was 3,013,622 on Sunday, 7th July. These dates show a consistent pattern where the highest volume occurs either during the late-June school-release window or the immediate post-July 4th return period. Notably, the actual holiday (July 4th) is typically one of the lowest volume days of the summer, as travelers remain at their destinations, creating a ‘coiled spring’ effect for the following Sunday.

Tailwinds

• The U.S. Semiquincentennial (250th anniversary) on 4th July 2026 is a ‘once-in-a-generation’ event expected to drive massive domestic travel to historic East Coast hubs.
• The 2026 FIFA World Cup (11th June – 19th July) will bring an estimated 6 million international visitors to 11 US host cities, significantly elevating baseline airport throughput.
• Major carriers reported record-high Q1 2026 revenues and ‘nine highest revenue intake weeks in history,’ suggesting an extremely high baseline of travel activity.
• The total solar eclipse on 12th August 2026 is expected to drive a surge in international departures toward the end of the observation window.
• Airlines are using ‘up-gauging’ strategies (larger aircraft) to handle demand despite fewer daily flight departures at restricted airports.

Headwinds

• High jet fuel prices (projected near $4.30 per gallon) have led airlines like Delta and United to implement ‘flat capacity’ plans, potentially limiting the number of seats available on peak days.
• The cessation of Spirit Airlines operations in May 2026 removed approximately 160 basis points of industry capacity, reducing options for ultra-low-cost travel.
• FAA-mandated caps on daily operations at major hubs like Chicago O’Hare (ORD) and Newark (EWR) could prevent volume from reaching theoretical demand peaks.
• Consumer sentiment reached a 20-month low in May 2026 (index of 44.8), which may temper non-essential leisure travel despite major events.

Detailed reasoning

My prediction for the peak US airline passenger volume is based on a rigorous analysis of historical TSA checkpoint seasonality, 2026 calendar configurations, and specific demand drivers.

The primary driver of the forecast is the ‘Sunday Peak’ phenomenon. Daily TSA data from 2019 to 2026 exhibits a strong 7-day periodicity (strength of 0.9525), with Sundays consistently recording the highest weekly throughput during the summer. In 2024, the summer peak occurred on Sunday, 7th July. In 2025, it occurred on Sunday, 22nd June. This pattern is driven by leisure travelers returning from weekend trips or week-long vacations before the workweek resumes.

For 2026, three specific Sundays emerge as the dominant candidates:

1. Sunday, 5th July 2026: This is the most probable date. Independence Day falls on a Saturday, which historically concentrates return travel into a massive single-day surge on Sunday. Furthermore, 2026 marks the U.S. Semiquincentennial (250th anniversary). Major celebrations in Philadelphia, Boston, and New York are expected to draw unprecedented crowds, the majority of whom will attempt to fly home on the 5th of July.
2. Sunday, 21st June 2026: This date coincides with the end of the Juneteenth long weekend (Friday, 19th June) and Father’s Day. Similar to the 22nd June peak in 2025, this represents the first major ‘summer surge’ as school terms end and holiday travel begins in earnest.
3. Sunday, 19th July 2026: This is the date of the FIFA World Cup Final at MetLife Stadium. While the World Cup lasts for weeks, the final typically creates a concentrated departure wave of international and domestic fans.

In my weighting, 5th July is the strongest candidate because holiday-return traffic (especially when the holiday is on a Saturday) consistently produces higher single-day throughput than sporting event departures. While airline capacity is projected to be relatively flat compared to 2025 due to fuel costs and the exit of Spirit Airlines, carriers like United and American are utilizing larger aircraft to maximize seat availability on these peak days. The upward trend in baseline passenger volume (+3,572 passengers per day since January 2026) suggests that the 2026 peak will likely exceed the 2025 record of 3.09 million passengers.

Key uncertainties

• Severe weather patterns, particularly summer thunderstorms in Southern hubs like Dallas (DFW) or Miami (MIA), can lead to mass cancellations that shift peak volumes to subsequent days.
• Potential labor disruptions, such as the ongoing Long Island Rail Road (LIRR) strike, could affect ground access to major New York area airports during peak windows.
• The ‘substitution effect’ cited by economists suggests the World Cup might displace some regular summer travel rather than adding entirely new volume, potentially muting the expected peak.
• Geopolitical tensions in the Middle East could further spike fuel prices, leading to more aggressive ‘off-peak’ flight cuts by major airlines.

Conclusion

• Decision-makers should prioritize Sunday, 5th July 2026, as the primary operational peak for the year, driven by the unique convergence of the Sunday holiday return and the U.S. 250th anniversary.
• While the FIFA World Cup and solar eclipse will drive significant international traffic, these are likely to elevate the summer baseline rather than shifting the single-day volume record away from the established holiday-return patterns.

Question: which single day between 2026-06-04 and 2026-08-12 will have the highest TSA checkpoint count? Forecasters agree the peak will come from a small set of holiday/event clusters rather than a smooth summer curve, with historical maxima concentrated in late June/early July (holiday-adjacent days) and Sundays and Fridays structurally strongest. Key candidate clusters are Juneteenth return (Sun 2026-06-21 / Mon 6/22), the July 4 departure/return cluster (Thu/Fri 7/02–03 and Sun/Mon 7/05–06, with Sun 7/05 singled out), and a mid-July World Cup / airline-schedule cluster (notably Fri 7/10, Fri 7/17 and Sun 7/19) supported by airline scheduling data. Numerical modeling of 2025 emphasizes Sunday dominance and places mass in mid/late July, but event-historian multi-year data pull the forecast toward the Juneteenth–July 7 band; forecasters synthesize by using weekday effects from the numeric agent while disciplining dates with multi-year history. Industry indicators (A4A, IATA, FAA) point to modest YoY passenger growth and Sunday/Friday concentration, while carrier capacity constraints and FAA caps (e.g., O’Hare) limit upside and make which cluster wins sensitive to where airlines preserve capacity. Forecasters assign minimal probability to an August day beating these clusters and a very small open-tail for the unlikely case of no usable TSA data by resolution.

Forecast and Reasoning

Forecast: Probability distribution:

• 10.00% chance of value below 2026-06-21 16:29:04 UTC
• 20.00% chance of value below 2026-06-28 22:30:40 UTC
• 40.00% chance of value below 2026-07-06 05:23:17 UTC
• 60.00% chance of value below 2026-07-13 04:40:59 UTC
• 80.00% chance of value below 2026-07-20 03:55:31 UTC
• 90.00% chance of value below 2026-07-27 02:59:28 UTC

Forecast Reasoning

Most historical TSA checkpoint throughput peaks in early/mid-summer have occurred on Sundays, reflecting return travel patterns, with notable concentration around (a) late-June ramp-up Sundays and (b) Sundays following the July 4 holiday period. For 2026, July 4 falls on Saturday (observed holiday Friday July 3), which likely produces a strong return-travel Sunday on July 5, but recent history suggests mid-July Sundays can match or exceed the post–July 4 Sunday when the holiday creates only a standard 3-day weekend. A key additional uncertainty for 2026 is the FIFA World Cup (June 11–July 19) potentially elevating baseline travel demand into mid-July, which increases the plausibility of July 12 or July 19 (and possibly the adjacent Monday) being the single-day peak. Balancing these factors, I keep most mass on the sequence of late-June through late-July Sundays, with a meaningful tail into early August, and very little weight on an open-after (>Aug 12) outcome because TSA daily data availability by Aug 17 is extremely likely.

An amateur forecast would often overcommit to a single salient date (e.g., July 4 itself or the immediate post-holiday Sunday) and underweight (1) the empirical Sunday dominance across many weeks and (2) calendar-specific drivers (3-day vs 4-day holiday structure) and special-event overlays (World Cup). This forecast improves calibration by spreading probability across the historically plausible competing Sundays (late June, post–July 4, mid-July), while still reflecting the strong base-rate weekday/seasonality pattern and keeping only a small tail into August.

Forecast rationale (numeric):

— Iteration 1 — Across the forecasts, the strongest consensus is that Sunday, July 5, 2026 is the most likely day to see the highest US airline passenger volume.

Main reasoning pattern

• Historical TSA travel patterns: Summer traffic peaks most often occur on Sundays, especially the return leg of holiday weekends.
• July 4 timing in 2026: Since July 4 falls on a Saturday, the federal holiday is observed on Friday, July 3, creating a long weekend that concentrates outbound travel on July 2–3 and return travel on Sunday, July 5.
• Return-travel effect: The day after a major holiday weekend is viewed as the most likely single-day spike because vacationers and short-trip travelers all come back at once.

Areas of consensus

• All forecasts converge on July 5 as the top candidate.
• All place the next-highest probabilities on nearby days, especially July 3, July 6, and July 2, reflecting split travel flows around the holiday.

Secondary possibilities

• Other summer Sundays are treated as fallback peaks, including June 28, July 12, July 19/20, and July 26.
• Juneteenth-related travel is also mentioned as a possible smaller peak in mid-to-late June.
• Late August and very early June are given little weight because they are outside the strongest seasonal travel window.

Overall synthesis

The forecasts are driven by a simple but powerful pattern: holiday-calendar effects plus the typical Sunday summer return peak. The main disagreement is not about the winner, but about how much probability to assign to nearby dates versus the central estimate. The collective view is that July 5, 2026 is the clearest single-day peak in the June 4–August 12 window.

— Iteration 2 — Overall, the forecasts converge on a summer travel peak driven by holiday timing and weekend return travel, with the strongest single-date candidate being Sunday, July 5, 2026 — the return-travel day after Independence Day weekend.

Main reasoning patterns

• Holiday-return Sundays dominate: Historical TSA/airline volume patterns are assumed to peak on the Sunday after a major summer holiday, especially July 4 and, secondarily, Juneteenth.
• Independence Day is the strongest anchor: Because July 4, 2026 falls on a Saturday, the following Sunday (July 5) is treated as the likeliest highest-volume day due to concentrated return travel.
• Summer weekends remain broadly elevated: Even outside holidays, mid-summer Sundays such as June 21, June 28, July 12, and July 19 are treated as high-probability candidates because summer leisure travel is seasonally strong.
• Event-driven boosts matter: The FIFA World Cup final on July 19, 2026 is seen as a possible additional demand driver, though usually secondary to holiday effects.
• Departure days can also be peaks: A smaller amount of weight is given to pre-holiday travel days like July 2, reflecting outbound travel before the July 4 weekend.

Areas of consensus

• The distribution is multimodal but concentrated on Sundays.
• July 5 receives the broadest support as the top candidate.
• June 21 is the main alternative peak because of Juneteenth and its placement on a Sunday.
• July 19 is a plausible later-summer contender, but usually not the primary one.

Main differences

• Some forecasts place the highest point probability on July 5, while others give slightly more weight to July 19 because of the World Cup final.
• There is mild disagreement over whether June 21 or July 5 is the strongest secondary peak, but all models treat both as major contenders.
• A few models also keep modest probability on late July/August or early June for anomaly/weather/operational reasons, though these are clearly lower-probability tails.

Bottom line

The collective view is that the highest passenger-volume day is most likely Sunday, July 5, 2026, with the forecast shaped primarily by holiday return travel, summer weekend seasonality, and a smaller event-driven boost later in July.

— Iteration 3 — Overall, the forecasts converge on Sunday, July 5, 2026 as the most likely day for the highest U.S. airline passenger volume.

Main reasoning pattern

• Independence Day timing is the dominant driver.
  • In 2026, July 4 falls on a Saturday, which makes Sunday, July 5 the natural return-travel peak after the holiday weekend.
  • The models rely heavily on the historical pattern that the Sunday after July 4 is often the busiest travel day when the holiday lands in a weekend configuration like this.

Secondary factors

• Heavy outbound travel on Friday, July 3 is the main competing candidate, since many travelers will depart before the holiday.
• Late-June and other nearby Sundays are treated as plausible alternatives because summer vacation travel can create strong weekend peaks.
• One model also gave meaningful weight to July 19 due to the 2026 FIFA World Cup Final, suggesting an event-driven spike could compete with the holiday pattern.
• A small tail of probability extends into mid-July and early August to allow for unusual disruptions or atypical travel timing.

Where the forecasts agree

• Strong consensus that the peak will fall in the late June to mid-July window.
• Strong consensus that the peak is most likely to be a Sunday, reflecting return travel behavior.

Where they differ slightly

• The main disagreement is not about the general window, but about which nearby day could challenge July 5:
  • July 3 for outbound holiday departures
  • July 6 for delayed return patterns
  • June 28 or July 12/19 as alternative summer/event peaks

Bottom line

The collective reasoning is anchored in holiday travel seasonality, especially the post-July-4 Sunday return surge, with secondary attention to outbound Friday travel and a few event-driven or adjacent-weekend alternatives.

The rationales broadly agree that the highest daily U.S. airline passenger volume in the summer of 2026 will almost certainly occur on a Sunday. Historically, summer Sundays create the most acute bottlenecks as returning leisure vacationers and departing business travelers converge. Forecasters highlight a few distinct calendar alignments and mega-events driving the 2026 peak:

• Independence Day & America 250 (Sunday, July 5): The strongest consensus centers on the post-July 4th return window. Because July 4, 2026, falls on a Saturday, the federal holiday is observed on Friday, July 3. This compresses the holiday into a strict three-day weekend, forcing a highly concentrated return wave on Sunday, July 5. This traditional bottleneck is heavily amplified by two unprecedented, overlapping events: the United States Semiquincentennial (America 250) celebrations drawing millions to historic East Coast hubs, and the 2026 FIFA World Cup Round of 16 matches.
• Juneteenth Weekend (Sunday, June 21): Recent trends show late-June Sundays frequently breaking all-time TSA records, driven by the alignment of summer school dismissals and uninterrupted corporate travel. In 2026, Juneteenth (June 19) falls exactly on a Friday, naturally creating a three-day weekend that requires no paid time off. The synchronized return travel on Sunday, June 21, is viewed as a formidable challenger to the July 4th window.
• World Cup Surges & Mid-July Baselines: Standard mid-summer Sundays are strong baseline contenders due to peak seasonal leisure demand. Specific World Cup milestones will act as massive regional multipliers. Forecasters highlight Sunday, June 28 (the mass travel transition following the World Cup Group Stages) and Sunday, July 19 (the World Cup Final in New Jersey) as days where international and domestic event traffic will uniquely strain the aviation system.
• Systemic Constraints: Finally, forecasters note that the absolute peak may be dictated by operational limits rather than raw demand. Air traffic control (ATC) shortages, airline capacity limits, and severe summer thunderstorms act as a ceiling on throughput. If adverse weather strikes the highest-demand days (like July 5), resulting cancellations could artificially suppress the TSA count, allowing an alternate weekend to claim the record.

SUMMARY

Question: Which day between June 4 and August 12, 2026, will see the highest US airline passenger volume? Final Prediction: Probability distribution:

• 10.00% chance of value below 2026-06-21 07:59:59 UTC
• 20.00% chance of value below 2026-06-28 08:00:00 UTC
• 40.00% chance of value below 2026-07-05 07:59:59 UTC
• 60.00% chance of value below 2026-07-05 07:59:59 UTC
• 80.00% chance of value below 2026-07-19 16:00:00 UTC
• 90.00% chance of value below 2026-07-26 08:00:00 UTC

Total Cost: extra_metadata_in_explanation is disabled Time Spent: extra_metadata_in_explanation is disabled LLMs: extra_metadata_in_explanation is disabled Bot Name: extra_metadata_in_explanation is disabled

Report 1 Summary

Forecasts

Forecaster 1: Probability distribution:

• 10.00% chance of value below 2026-06-21 23:59:59 UTC
• 20.00% chance of value below 2026-06-29 00:00:00 UTC
• 40.00% chance of value below 2026-07-05 23:59:59 UTC
• 60.00% chance of value below 2026-07-06 00:00:00 UTC
• 80.00% chance of value below 2026-07-20 00:00:00 UTC
• 90.00% chance of value below 2026-07-27 00:00:00 UTC

Forecaster 2: Probability distribution:

• 10.00% chance of value below 2026-06-20 23:59:59 UTC
• 20.00% chance of value below 2026-06-28 00:00:00 UTC
• 40.00% chance of value below 2026-07-04 23:59:59 UTC
• 60.00% chance of value below 2026-07-05 00:00:00 UTC
• 80.00% chance of value below 2026-07-19 00:00:00 UTC
• 90.00% chance of value below 2026-07-26 00:00:00 UTC

Forecaster 3: Probability distribution:

• 10.00% chance of value below 2026-06-20 23:59:59 UTC
• 20.00% chance of value below 2026-06-28 00:00:00 UTC
• 40.00% chance of value below 2026-07-04 23:59:59 UTC
• 60.00% chance of value below 2026-07-05 00:00:00 UTC
• 80.00% chance of value below 2026-07-20 00:00:00 UTC
• 90.00% chance of value below 2026-07-26 00:00:00 UTC

Research Summary

The research concludes that Sunday, July 5, 2026 is the single highest-probability candidate for peak TSA checkpoint passenger volume in the June 4–August 12, 2026 window. This conclusion is driven by a strong historical pattern that the Sunday after Independence Day is typically the busiest summer travel day, the 2026 calendar placing July 4 on a Saturday with the federal holiday observed Friday (creating a Friday–Sunday holiday weekend), NerdWallet and TSA historical analyses of years when July 4 fell on a Saturday showing the Sunday after as the peak return day, and an expected amplification from the U.S. 250th anniversary plus industry projections of record summer travel. Industry data and past TSA checkpoint records (including multiple >3M single-day counts in recent years) and airline capacity projections support a projected 2026 peak in the ~3.2–3.5 million passenger range.

The research also identifies alternate candidates (Monday July 6 for extended returns, Friday July 17 per American Airlines’ busiest-flight-day projection, and other late-July/early-August weekends) but treats them as less likely than July 5 based on historical Sunday-dominant return patterns, distinctions between flight operations versus TSA checkpoint throughput, and other uncertainties (timing of TSA releases, fuel-price impacts from geopolitical events, and weather disruptions). Secondary candidates and caveats are noted, and prediction-market behavior (Polymarket) is cited as evidence that TSA volumes are generally predictable.

Sources used in the research (websites referenced):

• Transportation Security Administration (TSA): https://www.tsa.gov
• American Airlines: https://www.aa.com
• United Airlines: https://www.united.com
• NerdWallet: https://www.nerdwallet.com
• Kayak: https://www.kayak.com
• Polymarket: https://polymarket.com
• Denver International Airport (for local passenger counts): https://www.flydenver.com

RESEARCH

Report 1 Research

Research Summary: Peak US Airline Passenger Volume, June 4 - August 12, 2026

Most Likely Peak Day: Sunday, July 5, 2026

Based on comprehensive research, Sunday, July 5, 2026 emerges as the highest-probability candidate for peak TSA checkpoint passenger volume within your specified window.

Base Rates and Historical Patterns

Strong Historical Pattern: Sunday After July 4th

The most consistent pattern in TSA data is that the Sunday following Independence Day is historically the busiest summer travel day [27]. This occurs because it captures the massive wave of return travelers from the holiday weekend.

Historical July 4th Weekend Peaks:

• July 7, 2024 (Sunday after July 4): Record 3,013,622 passengers - first time exceeding 3 million in a single day [29]
• July 6, 2025 (Sunday after July 4): Projected as busiest day with ~2.9 million passengers [12][14][25][27]
• July 6, 2025 (Denver alone): Over 99,000 passengers, marking one of the airport’s three busiest days in history [5]
• July 1, 2023 (Friday before July 4): Projected 2.82 million passengers [13]

2026 Calendar Alignment Creates Ideal Conditions

Critical Context: In 2026, July 4th falls on a Saturday [38][39][41], with the federal holiday observed on Friday, July 3 [39][41]. This creates a natural 3-day weekend (Friday-Sunday, July 3-5).

NerdWallet analyzed historical years when July 4th fell on Saturday (2009, 2015, 2020) and found that Sunday, July 5 consistently emerges as the peak return travel day [38]. The busiest travel days identified were:

• Before: Thursday, July 2 and Friday, July 3 (outbound travel)
• After: Sunday, July 5 (peak return travel) [38]

250th Anniversary Amplification Effect

2026 marks the 250th anniversary of the United States, which is expected to drive record airport crowds, especially in East Coast cities like Boston, New York, and Washington [38]. This commemorative context will likely amplify already-strong travel patterns around Independence Day.

Industry Projections for Summer 2026

Record-Breaking Volume Expectations:

• American Airlines: Record 75 million customers across 750,000 flights (May 21-Sept 8, 2026) [2][7][36]
• United Airlines: 53 million passengers June-August 2026, up 3 million from 2025 [6]
• TSA: 18.3 million screenings projected for Memorial Day weekend alone [8]
• Memorial Day weekend (May 21-26): 4.2 million passengers with Friday, May 22 as busiest day [2][36]

American Airlines specifically identifies July 17 as its busiest day with nearly 7,000 flights [2][7][32][36]. However, this refers to flight operations rather than TSA checkpoint throughput, and Friday patterns historically show lower checkpoint volumes than Sundays.

Alternative Peak Day Candidates

July 6, 2026 (Monday)

• Could capture extended weekend returns
• However, historical data shows Sunday consistently outperforms Monday [38]
• NerdWallet analysis indicates Monday-Wednesday (July 6-8) have “progressively smaller crowds” [38]

July 17, 2026 (Friday)

• American Airlines’ projected busiest flight day [2][7][32][36]
• Fridays are generally busy year-round [38]
• However, Sundays after major holidays typically exceed regular Fridays for TSA checkpoint volume

June 28-29, 2026 (Weekend before July 4)

• Heavy outbound travel expected [25][28]
• But return travel historically generates higher single-day volumes than outbound

Late July/Early August

• Kayak data shows interest spike around August 1 for final summer trips before school [31]
• Generally lower than July 4 weekend peaks

Prediction Market Context

While no specific markets were found for this exact question, Polymarket hosts numerous TSA passenger volume markets with strong liquidity and accuracy [18-24]:

• Historical accuracy: ~94% one month before resolution [18][21][23]
• Markets for weekly volumes show trading volume ranging from $238 to $464,078 [18][21]
• November 2025 Thanksgiving week market had $464,078 volume, indicating high trader confidence in TSA forecasting [21]

These markets demonstrate that TSA passenger volumes are highly predictable using historical patterns and seasonal analysis.

Volume Estimates

Projected Peak Day Volume:

• 2025 record: 3.1 million (June 22, 2025) [12][14][15][25][26]
• Given growth trends and 250th anniversary effect, 2026 peak could reach 3.2-3.5 million passengers
• The July 4 weekend period (July 1-7) is expected to exceed 2025’s 18.5 million total [12][25]

Key Uncertainties and Caveats

1. Data timing: As of June 3, 2026, TSA has not yet released specific July 2026 projections
2. External factors: The Iran war is driving up jet fuel prices [6][32], which could dampen demand somewhat
3. Weather disruptions: Extreme weather events could shift patterns [6]
4. Flight vs. passenger distinction: American’s July 17 projection is for flights, not TSA checkpoint throughput

Reference Class: Years When July 4 Falls on Saturday

Years analyzed: 2009, 2015, 2020 [38] Consistent finding: Sunday, July 5 is the peak return travel day when July 4 falls on Saturday

Final Assessment

Highest Probability: Sunday, July 5, 2026 Confidence Level: High (based on strong historical patterns and calendar alignment) Secondary Candidates: July 6 (Monday), July 17 (Friday)

The convergence of multiple factors—historical Sunday-after-July-4th pattern, 2026 calendar alignment creating a 3-day weekend, 250th anniversary amplification, and record growth trends—makes Sunday, July 5, 2026 the most evidence-backed forecast for peak passenger volume in your specified window.

FORECASTS

R1: Forecaster 1 Reasoning

Conditioning on non-annulment.

I accept the critic’s main calibration point: July 5, 2026 is the mode, but not dominant enough to put the 70th percentile at July 6. The strongest reason is the recent TSA reference class: in 2025, June 22 was the all-time peak and beat the post-July-4 Sunday; in 2024, July 7 won but June 23 was very close. That makes “another summer Sunday beats the holiday-return Sunday” a live failure mode, not just tail noise. (tsa.gov)

I still think July 5 deserves the single largest point mass. The 2026 setup is unusually clean: July 4 falls on Saturday, the federal holiday is effectively Friday July 3, and NerdWallet’s Saturday-July-4 reference analysis points to Sunday July 5 as the worst post-holiday return day; the America 250 overlay also plausibly adds some marginal July 4 travel demand. But that evidence is explicitly about the July 4 travel window, not the whole June 4–August 12 window, so I should not over-apply it. (nerdwallet.com)

I am moving more mass into two places. First, June 21: Juneteenth is Friday June 19, creating a three-day-weekend return Sunday in the same late-June seasonal slot that produced 2025’s record. Second, July 17–20: American Airlines says July 17 is its most-traveled summer 2026 day by flights, and the World Cup final is Sunday July 19 in the New York/New Jersey area. I still do not think either is enough to beat July 5 by itself, but together they make the post-July-6 right tail too important to compress. (news.aa.com)

My rough mental distribution is now: pre-July-5 about one-third, July 5 in the mid-30s, July 6 low-single digits, and post-July-6 around 30%. So I keep July 5 as the modal answer, but I adopt the critic’s broader CDF shape and push the 70th–95th percentiles later.

Updated prediction:
Percentile 0.1: 2026-06-04
Percentile 1: 2026-06-15
Percentile 5: 2026-06-22
Percentile 10: 2026-06-22
Percentile 20: 2026-06-29
Percentile 30: 2026-07-04
Percentile 40: 2026-07-06
Percentile 50: 2026-07-06
Percentile 60: 2026-07-06
Percentile 70: 2026-07-12
Percentile 80: 2026-07-20
Percentile 90: 2026-07-27
Percentile 95: 2026-08-03
Percentile 99: 2026-08-10
Percentile 99.9: 2026-08-12

R1: Forecaster 2 Reasoning

Conditioning on non-annulment, I still make Sunday, July 5, 2026 the modal and median forecast, but I agree with the critic that the original distribution was too “July 4 weekend deterministic” and too light on later July.

The strongest valid criticism is that “busiest July 4 return day” is not identical to “busiest day in the June 4–August 12 window.” In 2025, the in-window peak was Sunday, June 22 at 3,096,797, while several July/August dates were close: July 6, July 13, July 20, July 27, and August 1 were all very strong. In 2024, July 7 won, but June 23 was close; in 2023, the winner was Friday, June 30. This argues for a noisy cluster of high-capacity late-June-to-late-July days, not a single deterministic holiday-return spike. (archive.ph)

I still defend July 5 as the clear best single date. The 2026 calendar is unusually favorable: July 4 is a Saturday, Friday July 3 is the observed-holiday day for many workers, and NerdWallet’s TSA-based Saturday-July-4 reference-class analysis points to Sunday, July 5 as the key post-holiday return day. The 250th-anniversary context should raise Independence Day travel interest, though I agree it may also spread demand across surrounding days rather than purely concentrating it on July 5. (nerdwallet.com)

The critic’s point about airline capacity is also worth incorporating. American’s own summer 2026 schedule signal says its most-traveled day is Friday, July 17, with 6,995 flights, and July 10 is second, so I should give more weight to mid-July Fridays than I initially did. Likewise, the World Cup final on Sunday, July 19 plausibly adds tail risk to July 17–20, though I think the national TSA effect is likely modest relative to the broad summer/holiday base. (news.aa.com)

My updated rough point-probability picture is: July 5 around 32–35%, June 21 and June 28 around 7–9% each, July 12 / July 17 / July 19 each around 5–6%, and then smaller but nontrivial mass on July 6, July 10, July 20, July 24–26, July 31/August 2, and August 9. I reduce July 6: if July 5 misses, I now think the next-best alternatives are more likely later high-summer Sundays/Fridays, not Monday July 6.

Updated prediction:
Percentile 0.1: 2026-06-05
Percentile 1: 2026-06-18
Percentile 5: 2026-06-21
Percentile 10: 2026-06-21
Percentile 20: 2026-06-28
Percentile 30: 2026-07-05
Percentile 40: 2026-07-05
Percentile 50: 2026-07-05
Percentile 60: 2026-07-05
Percentile 70: 2026-07-12
Percentile 80: 2026-07-19
Percentile 90: 2026-07-26
Percentile 95: 2026-08-02
Percentile 99: 2026-08-09
Percentile 99.9: 2026-08-12

R1: Forecaster 3 Reasoning

Conditioning on non-annulment and TSA data being available, I accept the critic’s main correction: July 5 remains the modal date, but my prior distribution was too compressed around it.

The core July 5 case is still strong. July 4, 2026 falls on a Saturday, the federal holiday is observed Friday, July 3, and NerdWallet’s analysis of comparable July 4 calendars identifies Sunday, July 5 as the worst post-holiday travel day; it also flags the U.S. 250th anniversary as likely to make the holiday weekend especially busy. (nerdwallet.com) The 2024 precedent also supports this pattern: the Sunday after July 4, July 7, 2024, was the first TSA day above 3 million screenings. (nerdwallet.com)

But the critic is right that “busiest July 4 return day” is not the same as “busiest day in the whole summer window.” The 2025 case is especially sobering: TSA recorded 3,096,797 passengers on June 22, 2025, while the July 4 return Sunday was expected to be very busy but did not end up as the all-summer peak. (tsa.gov) This argues for a meaningful left-side probability on June 21/28 and not treating July 5 as a near-lock.

I also agree that July 17–20 deserves more mass. American Airlines says its most-traveled day of summer 2026 is July 17, with 6,995 flights, and its second-most-traveled day is July 10; that is not equivalent to national TSA throughput, but it is a real capacity/demand signal. (news.aa.com) The FIFA World Cup final at New York/New Jersey Stadium on Sunday, July 19, 2026 is too small by itself to move national TSA totals by hundreds of thousands, but it plausibly adds to a broader mid-July travel bulge, especially around July 17–20. (fifa.house)

My updated mental distribution is roughly: about one-third before July 5, high-20s percent on July 5 itself, and around 40% after July 5, with the strongest later cluster around July 17–20 and a smaller but nontrivial tail through July 26/August 2. I do not want to overdo the August tail, because early August is usually slightly past the national summer peak, but the 2025 near-3-million early-August readings make it too plausible to bury at the 99th percentile.

Updated prediction:
Percentile 0.1: 2026-06-07
Percentile 1: 2026-06-14
Percentile 5: 2026-06-21
Percentile 10: 2026-06-21
Percentile 20: 2026-06-28
Percentile 30: 2026-07-03
Percentile 40: 2026-07-05
Percentile 50: 2026-07-05
Percentile 60: 2026-07-05
Percentile 70: 2026-07-17
Percentile 80: 2026-07-20
Percentile 90: 2026-07-26
Percentile 95: 2026-08-02
Percentile 99: 2026-08-09
Percentile 99.9: 2026-08-12

Forecast — Post 419

Modal: Jun 29, 2026 to Jul 08, 2026 (52.0%) • partial_shift • 8m58s

Interpretation

Reading: strict

The resolution criteria are highly specific: a named URL, a fixed data-snapshot deadline (2026-08-17T00:00:00 UTC), a precise tie-breaking rule (earliest date), and explicit treatment of footnotes and missing data — leaving little room for charitable interpretation. The strict reading governs throughout: the resolver uses exactly the primary TSA table value at the snapshot time, no more and no less.

Time bounds

• observation_window: Daily TSA checkpoint passenger volumes for dates June 4, 2026 through August 12, 2026, as published on the TSA page by 2026-08-17T00:00:00+00:00
• resolution_date: 2026-08-17

Edge cases identified

1. If TSA retroactively revises data after 2026-08-17T00:00:00 UTC, revisions are ignored — only the snapshot at the deadline counts.
2. If some dates in the window are missing from the TSA table as of the snapshot, the peak is determined only from the available dates, meaning a missing date could have been the true peak but would not count.
3. Ties in volume resolve to the earliest date, which could matter if adjacent days (e.g., July 4 weekend days) post identical numbers.
4. The resolution criteria specify ‘primary daily value listed in TSA’s table for 2026, regardless of footnotes or potential corrections for system issues,’ meaning any asterisked or footnoted figures are still used at face value.
5. If the TSA.gov URL is unavailable, archived/alternative official sources are permitted, introducing ambiguity about which source takes precedence.
6. The anomalous fallback resolution ‘>2026-08-12T12:00:00+00:00’ if no data is available is unusual and may conflict with the annulment clause — edge case around what happens if partial (but not full-window) data is available.
7. Holiday weekends (July 4, Labor Day weekend overlap is outside window, but July 4 2026 falls on a Saturday making Friday July 3 and Sunday July 5 likely peak candidates) are key forecast anchors.

Research (3/3 variants, shared evidence pool)

Total evidence registered (shared pool): ?

Research Brief

Evidence confidence: medium

Scenario 1: Sunday July 5 or Monday July 6 as peak — July 4 weekend return surge [high evidence]

Conditions favoring

July 4 falls on Saturday 2026, making Sunday July 5 the natural first-return day and Monday July 6 the last-return day of the holiday weekend. Historical pattern from 2024 shows the Sunday after July 4 (July 7, 2024) was the all-time record. In 2025, Sunday July 6 was the peak of the July 4 weekend. If 2026 follows this return-Sunday/Monday pattern, July 5 or July 6 would be the peak within the window.

Conditions against

NerdWallet analysis of Saturday-July-4 years (2009, 2015, 2020) found those weekends are suppressed because people are already at their destinations by Saturday; the return-day surge may be less intense than a Monday/Friday July 4. FIFA World Cup demand may front-load travel into late June instead. 2026 volumes running ~4.56% below 2025 may suppress absolute numbers.

Scenario 2: Late June 2026 Sunday (e.g., June 21 or June 28) as peak — FIFA World Cup + pre-July-4 surge [medium evidence]

Conditions favoring

In 2025, the peak was June 22 (a Sunday in late June) at 3.097M — before the July 4 weekend. FIFA World Cup 2026 begins June 11 with ~6 million expected visitors, creating anomalous demand through late June and into July. If June 2026 replicates 2025’s pattern of an early-summer Sunday surge (amplified by FIFA), a late-June Sunday (June 21 or June 28) could set the window’s peak.

Conditions against

2026 volumes are running ~4.56% below 2025 year-over-year as of late May, potentially limiting how high a June Sunday can reach. FIFA visitors may spread across multiple weeks rather than concentrating on one day. The July 4 weekend still historically generates the highest absolute travel volumes.

Scenario 3: Friday July 3 as peak — outbound departure surge before July 4 Saturday holiday [medium evidence]

Conditions favoring

When July 4 is on a Saturday, many travelers depart Thursday or Friday (July 2–3) to reach destinations before the holiday. NerdWallet data shows Saturday July 4 is the least busy day in the period, implying the Friday before (July 3) may absorb the outbound peak. In 2024, TSA pre-weekend forecasts anticipated peak on Friday June 28 (before the actual Sunday peak), suggesting Fridays before holiday weekends are strong contenders.

Conditions against

2024 and 2025 both showed the actual peak was on a return Sunday, not the departure Friday. Historically, return-day volumes tend to exceed departure-day volumes for major holidays.

Scenario 4: Early August peak (first two weeks of August) — late-summer surge near window end [low evidence]

Conditions favoring

The resolution window extends through August 12. Some years show strong back-to-school travel in early August. If June and July volumes are suppressed (e.g., by the -4.56% YoY trend continuing), early August could emerge as the window peak by default.

Conditions against

Historical data consistently shows July (especially July 4 weekend) and late June as the highest-volume days of the summer. Per source 4, even Labor Day weekend (Aug 29, 2025) at 2.97M was well below the June/July peaks. No evidence suggests early August will outperform the July 4 holiday weekend or a FIFA-driven late June day.

Key uncertainties

• Whether the FIFA World Cup (June 11 – mid-July 2026) concentrates enough single-day air travel to push a late-June Sunday above the July 4 return-weekend peak
• Whether the Saturday placement of July 4, 2026 meaningfully suppresses the July 4 weekend peak relative to years when July 4 falls on other days
• Whether the ~4.56% YoY decline in 2026 volumes (as of late May) persists through peak summer, or whether it narrows/reverses by July
• Whether TSA data for all dates in the window will be published by the Aug 17, 2026 snapshot deadline (holiday-week delays noted in TSA’s own update schedule)
• The exact magnitude of FIFA’s day-to-day traffic concentration effect on U.S. airports, which has no direct historical precedent in the TSA dataset

Forecast variants (3/3)

Variant 0: inside_view (inside_view_v1)

Inside-View Causal Analysis

Current state → mechanism → outcome:

The question asks which specific date in June 4–Aug 12, 2026 will record the highest TSA checkpoint passenger volume.

Key causal facts:

1. July 4 falls on Saturday 2026 (authoritative calendar sources). Per NerdWallet analysis of years when July 4 fell on Saturday (2009, 2015, 2020), the Saturday July 4 itself is “typically the least busy day to fly in the entire 13-day period.” This means the July 4 2026 holiday travel peak shifts to: Friday July 3 (outbound) and Sunday July 5 / Monday July 6 (return).

2. Historical return-day pattern dominates (high-strength evidence):

   • 2024: Peak was Sunday July 7 (return day after July 4 weekend) — first 3M+ day in TSA history
   • 2025: Sunday July 6 was the busiest July 4 weekend day (source 8, authoritative)
   • Pattern: Sunday after July 4 holiday is consistently the peak for that holiday

3. FIFA World Cup 2026 begins June 11 (authoritative, TSA press release). ~6 million visitors expected. This creates anomalous late-June demand. In 2025 (without FIFA), June 22 set the all-time record at 3.097M. With FIFA, a late-June Sunday (June 21 or June 28) is a legitimate competitor.

4. 2026 volumes running ~4.56% below 2025 (source 20, non-authoritative). This moderates absolute peak expectations but doesn’t change the relative pattern of which day peaks.

Bin mapping:

• Jun 29–Jul 08 (bin_3): Contains July 5 (Sunday) and July 6 (Monday) — the high-strength scenario of July 4 weekend return days. Also contains July 3 (Friday outbound). This is the single most concentrated mass bin based on the high-evidence scenario.

• Jun 21–Jun 29 (bin_2): Contains June 21 (Sunday) and June 28 (Sunday) — the late-June FIFA-driven Sunday peak scenario. Medium-strength evidence (2025 precedent + FIFA).

• Jul 08–Jul 17 (bin_4): Contains July 8–9 (Mon/Tue after July 4 weekend could spill), lower probability. Slight mass.

• Jun 12–Jun 21 (bin_1): Contains June 14, 21 (Sundays during FIFA group stage). Some FIFA travel demand. Minor mass.

• Jun 03–Jun 12 (bin_0): Window start (Jun 4–12), early FIFA days. Very low probability for summer peak.

• bins 5-12: Post-July-peak bins. August volumes historically lower than June/July peaks. Very low mass.

Weighting by evidence strength:

• High-evidence scenario (Sunday July 5 or Monday July 6 = bin_3): ~45%

  • This maps directly to July 3 (outbound, Friday), July 5 (return Sunday), July 6 (return Monday) — all in Jun 29–Jul 08 (bin_3)

• Medium-evidence scenario A (Late June Sunday = bin_2): ~25%

  • June 21 or June 28 as FIFA-boosted peak

• Medium-evidence scenario B (Friday July 3 = bin_3): Already included in bin_3

• bin_1 (mid-June FIFA-driven): ~8%

• bin_0 (early June): ~3%

• bin_4 (Jul 8–17, spillover): ~8%

• bin_5 (Jul 17–26): ~3%

• bin_6 (Jul 26–Aug 3): ~3%

• bin_7 (Aug 3–12): ~3%

• bins 8-12: ~2% total (data availability edge cases, out-of-window resolution)

Final allocation:

bin_3 is the modal bin due to high-strength evidence placing July 5 (return Sunday) and July 6 (return Monday) as likely peak. The July 3 Friday outbound surge also falls here. Total ~47%.

bin_2 gets meaningful mass (~22%) for the FIFA/late-June scenario supported by 2025 precedent.

Remaining bins get smaller allocations reflecting low-evidence scenarios.

Variant 1: outside_view (outside_view_v1)

Reference class: U.S. TSA daily summer peak days in recent years (late-May through mid-August windows). Base rate: about 65% that the single busiest summer day falls in the late-June / early-July period (e.g., 2024 peak = Sunday July 7; 2025 peak = Sunday June 22) (sources: TSA press releases cited in the brief, sources 2, 3, 6, 9). Adjustment: +15 percentage points toward the early-July cluster because two resolver facts increase the chance this year that the return-day of the July-4 weekend or the immediately adjacent days will be dominant — (a) July 4, 2026 is a Saturday, which historically shifts the busiest day to the return Sunday/Monday (NerdWallet/TSA patterns; sources 7, 17, 8), and (b) FIFA World Cup travel beginning June 11 (TSA noted ~6M visitors; sources 18, 19) raises the chance of a late-June spike but primarily strengthens the broad late-June/early-July window rather than a single oddball day. Final (outside-view) combined probability that the peak falls in the late-June OR early-July window (bins covering Jun21–Jul08) = 80% (bin_2 + bin_3 = 0.25 + 0.55). Because the brief labels the July-weekend-return scenario “high” evidence, I place the largest single-bin mass on Jun 29–Jul 08 (bin_3) at 55% — this covers the Friday–Monday July 3–6 return/outbound cluster (sources 6, 7, 8, 17). Medium-evidence scenario (FIFA-driven late-June Sunday, sources 3, 18, 19) receives the next largest mass on Jun 21–Jun 29 (bin_2) at 25%. Lower but non-negligible probability is allocated to early/mid-June (bin_0 and bin_1 combined 8%) to reflect some World Cup front-loading and regular summertime spread (sources 15, 16, 18). Small tails (bins 4–7 each 2–4%) cover the modest chance that the busiest day occurs slightly later in July or in early August (evidence strength low for those outcomes; source 4 shows Labor Day peaks are usually below June/July peaks). A 2% tail is assigned to Aug 12–Oct 21 (bin_8) to capture the low-probability operational/data risk or the specific fallback in the resolution criteria (e.g., missing data / resolution falling to the >Aug12 fallback). Confidence in evidence: medium (the brief flags medium confidence and important uncertainties — YoY -4.56% trend, FIFA concentration unknown, and TSA publish/delay risk; sources 20 and the brief’s key_uncertainties). Per the brief’s instruction to follow a strict reading of the resolver source, this distribution assumes the resolver will use exactly the TSA passenger-volumes table snapshot as of 2026-08-17 and that any tie-breaks go to the earlier date (ties thus slightly favor earlier days inside the same bin).

Variant 2: contrarian_v2 (contrarian_v2)

Adversarial reading

The bulk of the evidence in the brief pulls toward Jun 29–Jul 08 (bin_3) via the high-evidence scenario of a July 4 weekend return surge on July 5 or 6, 2026. This is anchored in the 2024 and 2025 historical patterns where the Sunday after July 4 was the summer peak, combined with July 4 falling on a Saturday.

Counter-evidence found (or absence)

Counter-evidence exists in the medium-evidence FIFA World Cup scenario (sources 3, 9, 18, 19) that could shift the peak to late June (bin_2) by replicating the June 22, 2025 pre-holiday Sunday record. The ~4.56% YoY volume decline and lack of direct precedent for FIFA’s single-day concentration effect weaken the July 4 dominance relative to a pure historical reading.

Distribution implications

I therefore shift ~22% mass into late June (bin_2) — more than a naive consensus would assign — while still placing the plurality (52%) on bin_3. Thin evidence for early August or post-window annulment keeps those bins low but non-zero.

Consolidate

Strategy: logit_mean • Drafts: 3/3

Reviewers (3/3)

anchoring → shift_lower (low magnitude, medium confidence) anchoring_v1

The draft places 52% of mass in Jun 29–Jul 08 (bin_3), which covers July 3–6. The rationale correctly identifies July 5 (Sunday) and July 6 (Monday) as the modal return-day candidates, but the 52% modal bin assignment reflects solid historical reasoning rather than anchoring error per se. However, I detect a mild optimistic-end anchoring in Jun 21–Jun 29 (bin_2) at ~23%: the brief repeatedly frames the FIFA World Cup as an “additional unique demand driver” that could replicate the June 22, 2025 record, but the 2025 June 22 peak occurred without FIFA — FIFA 2026 is a new variable whose concentration effect on single-day U.S. airport throughput is entirely uncharted. The draft treats the 2025 June peak + FIFA as compounding positives and places 23% on late-June bins, which overshoots the evidence-thin nature of the FIFA concentration claim. The modal expectation under a flat-prior interpretation of FIFA’s effect (spread across many weeks, not concentrated on one day) would assign closer to 15% to bin_2. Additionally, Jul 08–17 (bin_4) at only ~5.5% seems slightly under-weighted given that “spillover” days (July 8–9) from a Saturday-holiday weekend are plausible secondary peaks.

Flagged concerns

• FIFA optimistic anchoring: The draft assigns ~23% to Jun 21–Jun 29 (bin_2) largely by combining the 2025 late-June precedent with the FIFA World Cup as an amplifier. But the brief explicitly flags ‘The exact magnitude of FIFA’s day-to-day traffic concentration effect on U.S. airports has no direct historical precedent in the TSA dataset.’ Treating FIFA as a multiplier on an already-extreme single-day peak inflates bin_2 above what a neutral flat-prior reading of the evidence would support (~15% is more appropriate).
• Within-bin distribution of July 4 weekend candidates: Bin_3 covers June 29–July 8 and correctly captures July 3 (Friday outbound), July 5 (Sunday return), and July 6 (Monday return). The 52% mass in this bin is consistent with the high-evidence scenario, but the rationale does not explicitly acknowledge that July 3 (Friday outbound) is historically weaker than return-day Sundays (sources 6 and 8 both show Sunday as peak, not Friday), so the intra-bin distribution is slightly anchored toward a wider set of candidates than the evidence supports for the modal day.

ceiling → redistribute (low magnitude, medium confidence) ceiling_v1

The brief surfaces a structural ceiling on the July 4 weekend’s peak-day magnitude: NerdWallet’s analysis of the three prior Saturday-July-4 years (2009, 2015, 2020) found Saturday July 4 is “typically the least busy day to fly in the entire 13-day period,” implying the adjacent holiday-weekend days are also relatively suppressed versus years when July 4 falls on a weekday. Yet the draft still places 52% in Jun 29–Jul 08 (bin_3) by mechanically applying the 2024/2025 Sunday-return pattern without discounting for the Saturday-July-4 structural dampener. More critically, bin_3 spans Jun 29–Jul 08, which means it also captures July 3 (the outbound Friday) and July 7–8 (the following week) — but the July 4 Saturday placement means peak-return pressure is split between July 5 and July 6, both of which are in bin_3. This is actually not a ceiling violation per se; bin_3 IS the right concentration zone. The structural concern instead is that the draft under-weights the hard floor argument: the window includes the entire FIFA World Cup group stage period through late June, and in 2025 (without FIFA) the June 22 Sunday already beat the July 4 weekend. With FIFA adding ~6M visitors, the late-June bins (bin_1, bin_2) likely deserve modestly more mass than the draft gives them relative to the structurally-capped July-Saturday-4 weekend. The August bins (bin_7) are likely over-weighted at ~2.9% given that Labor Day 2025 (a strong August weekend) reached only 2.97M versus 3.097M for June 22, 2025 — establishing a structural ceiling that makes bins 5–12 implausibly high collectively at ~8%.

Flagged concerns

• Structural ceiling on July-Saturday-4 weekend magnitude: The brief cites NerdWallet analysis of years when July 4 fell on Saturday (2009, 2015, 2020): ‘Saturday July 4 is typically the least busy day to fly in the entire 13-day period.’ This structural dampener applies to the entire July 4 2026 weekend cluster, not just July 4 itself. The draft allocates ~52% to Jun 29–Jul 08 (bin_3) without adequately discounting for this structural ceiling on the holiday weekend’s peak-day magnitude relative to non-Saturday-July-4 years. The 2024 and 2025 precedents used to anchor bin_3 were NOT Saturday-July-4 years.
• Under-weighting of FIFA-driven structural floor in late June bins: The brief establishes that: (1) In 2025 without FIFA, June 22 beat the July 4 weekend outright at 3.097M. (2) FIFA adds ~6M visitors beginning June 11, 2026. This creates a structural upward pressure on Jun 12–Jun 21 (bin_1) and Jun 21–Jun 29 (bin_2) that the draft under-represents at only 4.8% and 23.4% respectively. Given that the June 22 Sunday in 2025 was the all-time record even without FIFA, and 2026 adds FIFA on top, bin_2 in particular may deserve closer to 28-30%.
• Excessive mass in late-window bins (bin_5 through bin_12): The draft allocates ~10.5% collectively to bins 5–12 (Jul 17 onward). The brief’s authoritative fact states Labor Day 2025 (Aug 29) reached only 2.97M — well below the 3.097M June/July peaks. This structural ceiling means the probability of any day in late July or August exceeding the June/July peak cluster is very low. Bins 5–7 should collectively be under 5%, not ~8.2%.

math → no_change (low magnitude, medium confidence) math_v1

The draft forecast has a significant math inconsistency in its bin allocation logic. The rationale explicitly states “bin_3 is the modal bin due to high-strength evidence placing July 5 (return Sunday) and July 6 (return Monday) as likely peak. Total ~47%,” yet the draft distribution assigns 52.19% to Jun 29–Jul 08 (bin_3). More critically, the inside-view rationale allocates 45% to the high-evidence scenario AND separately allocates medium-evidence scenario B (Friday July 3, also in bin_3) without explicitly reconciling how much of the 47% target accounts for overlap—the two variants reach bin_3 totals of 47% and 55%, but the consolidated draft lands at 52.19%, suggesting the logit_mean averaging has been applied without explicit decomposition. The distribution sums to 1.0 correctly, but the modal bin’s justification is internally ambiguous about whether the 52% already includes the Friday July 3 component or not.

Flagged concerns

• Modal bin justification ambiguity: Rationale says bin_3 should be ~45–47% (high-evidence July 4 weekend return peak), but draft assigns 52.19%. Inside-view says Friday July 3 is ‘already included in bin_3,’ yet the allocation to Friday vs. Sunday July 5/6 split is never explicit. Unclear whether the 52% reconciles overlapping Friday/Sunday scenarios or double-counts.
• Scenario mass reconciliation: Rationale allocates: bin_3 ~47%, bin_2 ~22%, bin_1 ~8%, bin_0 ~3%, bin_4 ~8%, bin_5 ~3%, bin_6 ~3%, bin_7 ~3%, bins 8-12 ~2%. These sum to 99%, but draft shows bin_3=52.19%, bin_2=23.35%, bin_4=5.53%, bin_1=4.81%, bin_0=2.67%, bin_5=2.67%, bin_6=2.67%, bin_7=2.94%, bin_8=1.62%, bin_9=0.22%, bin_10=0.60%, bin_11=0.37%, bin_12=0.00%. The allocation to 5.53% in draft vs. 8% in rationale (bin_4) and the shift into 52% vs. 47% (bin_3) suggest either the inside-view targets were not binding or logit_mean smoothed them in a way not explained.
• Outside-view anchoring drift: Outside-view variant states it places 55% on bin_3 and 25% on bin_2, which would sum to 80% for the late-June/early-July window. Draft shows 52.19% + 23.35% = 75.54% for the same window. The 4.46pp shortfall is distributed to other bins; this is plausible logit_mean behavior but creates a small coherence gap between stated outside-view allocations and the final draft.

Reconcile: partial_shift

Reviews consumed: 3

All three reviewers converge on Jun 29–Jul 08 (bin_3) as the modal bin at ~50-57%, with Jun 21–Jun 29 (bin_2) as the secondary at 15-27%. The anchoring reviewer flagged FIFA-as-amplifier as optimistic anchoring and suggested trimming bin_2 toward ~15%, while the ceiling reviewer argued the opposite — that bin_2 deserves MORE mass (~27%) given the 2025 June 22 record + FIFA tailwind plus the Saturday-July-4 structural dampener. These directly oppose each other, so I split the difference near the draft’s ~23%, leaning slightly higher to honor the ceiling reviewer’s stronger structural argument (the 2025 precedent without FIFA already beat July 4, which is a hard data point, not speculation). The ceiling reviewer’s concern about over-weighted late-window bins (5-12) is well-supported by the Labor Day 2025 ceiling fact — I trimmed bins 5-12 modestly. The math reviewer flagged ambiguity in bin_3 allocation but suggested no_change in direction; I accept the consolidated ~52% as a reasonable logit-mean output. Net effect: small redistribution from late-window tail bins into bin_2 and slightly into spillover from holiday weekend (bin_4), keeping bin_3 as the clear mode.

Rejected critiques

• [anchoring] FIFA-as-amplifier inflates bin_2 above ~15% flat-prior baseline; bin_2 should be closer to 15%.

  • Why rejected: The ceiling reviewer made a stronger opposing case: the 2025 June 22 Sunday set the all-time record WITHOUT FIFA, establishing a hard data floor that doesn’t depend on speculative FIFA concentration. Trimming bin_2 to 15% would dismiss this concrete precedent. I kept bin_2 near 24.5% — between the anchoring reviewer’s 15% and ceiling reviewer’s 27%.

• [math] Bin_3 at 52% may not cleanly reconcile with inside-view’s stated 47% target due to logit_mean smoothing and unclear Friday-July-3 vs. Sunday-July-5 decomposition.

  • Why rejected: Math reviewer explicitly suggested no_change in direction and its independent forecast also lands at ~50% on bin_3. The ambiguity is about internal accounting, not external accuracy — logit_mean across three variants (47%, 55%, 52%) producing 52% is mathematically valid even if the inside-view scenario decomposition was imprecise.

Final Distribution (date ranges)

Evidence Sources (21)

1. Auto-prepended resolver source — Auto-prepended source-query: https://www.tsa.gov/travel/passenger-volumes (fetched 2026-06-03T23:04:22.294325Z). value=nil. Excerpt: TSA checkpoint travel numbers | Transportation Security Administration

2. Home

3. Travel

4. TSA checkpoint travel numbers

TSA checkpoint travel numbers

Passenger travel numbers are updated Monday through Friday by 9 a.m. Travel numbers during holiday weeks though may be slightly delayed.

| 5/7/2026 | 2

2. TSA Officers support record summer screening at nation’s airports — On July 7, 2024, TSA screened more than 3 million passengers in a single day — the first time in TSA’s history — during the July 4 holiday weekend. This was the all-time single-day record as of that date.
3. TSA expects over 18.5 million people to travel by air over busy Fourth of July holiday (June 24, 2025) — On June 22, 2025, TSA screened nearly 3.1 million travelers — the busiest single day in the agency’s history as of June 2025. This was on a Sunday and set the all-time record before the July 4 holiday.
4. TSA screens record 10.4 million individuals over Labor Day weekend (Sept 3, 2025) — On Aug. 29, 2025 (Friday before Labor Day), TSA screened 2,971,217 passengers, the 15th busiest single day in agency history — less than the June/July peaks. Eight of the top 10 busiest days occurred since May 23, 2025.
5. The Busiest Travel Days of the Year, According to TSA - AFAR (Nov 2025) — AFAR data (Nov 2025) lists the 15 busiest travel days including: June 22, 2025: 3.097M passengers; December 1, 2024: 3.089M; and July 7, 2024 (Sunday) at ~3.04M (first day ever to exceed 3M in summer). The 2024 summer peak was July 7, 2024 — the Sunday returning from July 4 weekend.
6. Statement from Secretary Mayorkas on Record Three Million Screenings by TSA (July 8, 2024) — In 2024, the summer peak travel day was Sunday July 7 — the return day of the July 4 holiday weekend. TSA’s anticipation before that weekend was that peak would be Friday June 28, but the actual peak was the following Sunday (July 7), which was the first day in TSA history to exceed 3 million passengers.
7. wincalendar.com July 4, 2026 — July 4, 2026 falls on a Saturday. This means July 3 (Friday) and July 5 (Sunday) are key peak-travel candidates for the July 4 holiday weekend. July 6 (Monday) would be the return day. The window of maximum travel pressure falls around July 3-6, 2026.
8. TSA ready for busy summer travel season at Colorado airports (May 19, 2026) — In 2025, Sunday July 6 was the busiest single day during the July 4th holiday weekend at the national level, confirming that Sunday after July 4 tends to be the peak. At Denver International, July 6, 2025 was their record-setting day with 99,000+ travelers, and “Sundays are typically the busiest screening days at DEN throughout the summer.”
9. AFAR - The Busiest Travel Days of the Year (Nov 2025) — In 2025, the summer peak (within the June-August window) was June 22, 2025 (Sunday) with ~3.097 million — BEFORE the July 4 holiday weekend (July 6 was only ~2.9M projected). This shows the peak can fall outside the July 4 weekend in years where June volume is exceptionally high.
10. TSA checkpoint travel numbers — Per the resolver-named TSA page, passenger travel numbers are updated Monday–Friday by 9 a.m., with possible slight delays during holiday weeks.
11. Resolution criteria — resolver-named source — Per the resolution criteria, the authoritative resolver source is the TSA checkpoint travel numbers page at https://www.tsa.gov/travel/passenger-volumes (the question names this URL).
12. Auto-prepended resolver source fetch — Auto-prepended fetch of the resolver-named source (https://www.tsa.gov/travel/passenger-volumes) was performed before this research turn; the system recorded an excerpt of the TSA page showing daily numbers up through at least 5/17/2026 (e.g., 5/17/2026: 2,887,942), but the extracted value field returned nil. (Auto-prepended source evidence)
13. TSA checkpoint travel numbers page — TSA passenger travel numbers are updated Monday through Friday by 9 a.m., and travel numbers during holiday weeks may be slightly delayed — per the TSA checkpoint travel numbers page (https://www.tsa.gov/travel/passenger-volumes).
14. WinCalendar / TimeandDate (calendar) — July 4, 2026 falls on a Saturday — meaning the associated holiday travel peak may shift to the Friday (July 3) before and the Sunday (July 5) after — per calendar sources (WinCalendar/timeanddate).
15. TSA checkpoint travel numbers | Transportation Security Administration — TSA checkpoint travel numbers for June 1, 2026 show 2,674,187 passengers screened, the earliest June 2026 daily figure published on the TSA passenger volumes page.
16. TSA checkpoint travel numbers | Transportation Security Administration — The TSA passenger volumes page (as of early June 2026) shows the most recent entries are 6/1/2026: 2,674,187; 5/31/2026: 2,818,994; 5/30/2026: 2,307,047; 5/29/2026: 2,689,872 — confirming the dataset is current and actively being updated into June 2026.
17. The Best Days to Fly Around July Fourth - NerdWallet — NerdWallet analyzed TSA checkpoint data from 2009, 2015, and 2020 — the last three years when July 4 fell on a Saturday — to forecast 2026 travel patterns, finding that Saturday, July 4 is “typically the least busy day to fly in the entire 13-day period” around the holiday, with most people already at their destinations by then.
18. TSA readies for summer travel season kickoff | Transportation Security Administration — TSA’s May 20, 2026 national press release projected 18.3 million passengers and crew screened during the Memorial Day period (May 21–27, 2026), kicking off the summer travel season, and specifically noted FIFA World Cup 2026 begins June 11, expected to bring ~6 million visitors to the U.S.
19. TSA readies for summer travel season kickoff | Transportation Security Administration — The FIFA World Cup 2026 kicks off June 11, 2026 in North America at 11 U.S. stadiums, with the tournament overlapping peak summer travel season (late June–early July), creating a unique demand driver for June 2026 airport volumes beyond typical seasonal patterns.
20. US - TSA Checkpoint Travel Numbers - MacroMicro — MacroMicro data shows TSA checkpoint travel numbers year-over-year change for 2026-05-28 was -4.56% (current year vs. prior year), suggesting 2026 volumes are running slightly below 2025 levels as of late May 2026.
21. TSA checkpoint travel numbers | Transportation Security Administration — TSA reported that May 17, 2026 had 2,887,942 passengers — the highest single day captured in the published spring 2026 dataset — while the May 2026 range broadly ran from ~2.0M (low days) to ~2.89M (peak days), establishing a pre-June 2026 baseline for comparison.

wooley_rhino • run 0385411c • $2.9 • 8m58s

Extracted Date Percentile Values: {0.1: 1780617600.0, 1.0: 1781395200.0, 5.0: 1781827200.0, 10.0: 1782000000.0, 15.0: 1782000000.0, 20.0: 1782000000.0, 25.0: 1782345600.0, 30.0: 1782432000.0, 35.0: 1782604800.0, 40.0: 1782950400.0, 45.0: 1782950400.0, 46.0: 1782950400.0, 47.0: 1783036800.0, 48.0: 1783036800.0, 49.0: 1783036800.0, 50.0: 1783209600.0, 51.0: 1783209600.0, 52.0: 1783209600.0, 53.0: 1783209600.0, 54.0: 1783209600.0, 55.0: 1783209600.0, 60.0: 1783209600.0, 65.0: 1783209600.0, 70.0: 1783209600.0, 75.0: 1783296000.0, 80.0: 1783641600.0, 85.0: 1783814400.0, 90.0: 1784246400.0, 95.0: 1784419200.0, 99.0: 1785628800.0, 99.9: 1786233600.0}

Model’s Answer: Step one is to pin down the actual support of the question. This resolves to a single daily TSA checkpoint date, so the only meaningful outcomes are the discrete calendar dates from 2026-06-04 through 2026-08-12 inclusive. There is also a very remote fallback outcome after 2026-08-12 if no TSA data for the whole window is available by 2026-08-17, but that looks far too unlikely to affect any reported percentile.

Step two is to lean hardest on the most relevant evidence. The strongest signal in the research is that recent summer peaks have clustered on Fridays and Sundays, especially around late June, Independence Day, and very high-volume return days. The most important update is 2025: a Sunday, 2025-06-22, reportedly set a new TSA record, which means a late-June holiday return day can absolutely beat the July 4 complex. That materially boosts 2026-06-21, the Sunday after a Friday Juneteenth.

Step three is the 2026 calendar structure. Juneteenth is Friday, 2026-06-19, which creates a clean three-day weekend and makes Sunday, 2026-06-21, a very strong candidate. Independence Day is Saturday, 2026-07-04, with Friday, 2026-07-03, commonly observed as the holiday, which makes Thursday, 2026-07-02, Friday, 2026-07-03, and especially Sunday, 2026-07-05, the core July 4 candidates. I give 2026-07-05 the single highest probability because July baseline demand is a bit higher than June and Sunday return days are structurally strong, but I do not make it overwhelmingly dominant because 2025 showed late June can win.

Step four is to widen out to plausible alternatives. If the holiday peaks are more diffuse than expected, then the next most likely winners are late-June and mid-July Fridays/Sundays, especially 2026-06-26, 2026-06-28, 2026-07-10, 2026-07-12, and 2026-07-17/19. Early June is possible only under fairly unusual circumstances. Early August is a tail case if the peak shifts later into pure summer leisure travel, but historical patterns suggest some taper by then.

The assumptions most likely to matter are that 2026 follows the same broad post-2023 TSA pattern of holiday-adjacent Friday/Sunday dominance, which I think has about a 30% chance of being materially less true than I expect; that Juneteenth 2026 is a useful analog to the June 2025 surge, which has about a 35% chance of being a worse analog than it appears; and that there is no nationwide disruption or data issue large enough to scramble the ranking, which I put around 5%. I account for those failure modes by keeping a meaningful tail into mid and late July and a small tail into early August.

For “earlier versus later,” relative to my modal cluster around the July 4 period, I put about 49.5% on a peak before 2026-07-05, about 24.5% exactly on 2026-07-05, and about 26.0% after 2026-07-05. An earlier outcome mainly comes from the Juneteenth return weekend, especially 2026-06-21, or from late-June peaks continuing the 2025 pattern. A later outcome mainly comes from July 4 travel spreading out enough that mid-July weekends become the top days.

Percentile .1: 2026-06-05 Percentile 1: 2026-06-14 Percentile 5: 2026-06-19 Percentile 10: 2026-06-21 Percentile 15: 2026-06-21 Percentile 20: 2026-06-21 Percentile 25: 2026-06-25 Percentile 30: 2026-06-26 Percentile 35: 2026-06-28 Percentile 40: 2026-07-02 Percentile 45: 2026-07-02 Percentile 46: 2026-07-02 Percentile 47: 2026-07-03 Percentile 48: 2026-07-03 Percentile 49: 2026-07-03 Percentile 50: 2026-07-05 Percentile 51: 2026-07-05 Percentile 52: 2026-07-05 Percentile 53: 2026-07-05 Percentile 54: 2026-07-05 Percentile 55: 2026-07-05 Percentile 60: 2026-07-05 Percentile 65: 2026-07-05 Percentile 70: 2026-07-05 Percentile 75: 2026-07-06 Percentile 80: 2026-07-10 Percentile 85: 2026-07-12 Percentile 90: 2026-07-17 Percentile 95: 2026-07-19 Percentile 99: 2026-08-02 Percentile 99.9: 2026-08-09

Annual summer air traffic is bounded by physical capacity, carrier schedules, and a persistent late‑June–early‑July weekday shape.

Historical peaks concentrate in a narrow calendar band where weekend returns and holiday windows overlap, with very small margins between candidate days.

The 2026 calendar stacks a Friday holiday cadence and a multi‑day national celebration into July 1–5, amplifying the post‑holiday Sunday return pressure.

A Juneteenth Friday and a major international final on July 19 add parallel late‑June and mid‑July return pressures that elevate nearby Sundays.

If return travel concentrates after the national celebration and the observed holiday stays on the preceding Friday, the Sunday immediately after (July 5) is the likeliest single‑day high.

If outbound flows instead peak before holidays or event travel front‑loads departures, a late‑June Sunday or the July 19 weekend can overtake that candidate.

Key uncertainties include the short post‑2019 daily record and pandemic‑era anomalies in the analog sample, which weaken cross‑year inference.

Operational shocks—weather, ATC constraints, airline schedule changes, or IT outages—and the precise timing of concentrated returns are the primary sensitivities that can flip the winner.

Forecast: July 5, 2026

• Holiday timing: July 4 lands on a Saturday (with the observed holiday on Friday), which tends to concentrate travel into the following weekend. The strongest “return surge” is expected to hit on Sunday, July 5.
• Sunday pattern: Across recent years, the single biggest TSA day in summer has very often been a Sunday, suggesting day-of-week is a powerful driver of the maximum.
• Juneteenth backup contender: June 21 (the Sunday after Juneteenth) is also a serious candidate because an analogous date in 2025 produced an extreme peak—but 2026’s Juneteenth setup is expected to be a bit less intense.
• Mid-July risk from the World Cup: July 19 (World Cup Final Sunday) could push a competing peak higher, but the forecast treats it as slightly less likely than the July 5 holiday-return surge.
• Overall expectation: The model’s balance of calendar effects and historical “where the top day usually falls” points to July 5 as the most likely day to be the nationwide maximum.