On one Sunday in January, almost half of US flights were cancelled

Last checked 7 October 2026

On 25 January 2026, 46.5% of scheduled departures by US airlines that report to the US Department of Transportation's on-time data (BTS) were cancelled: 8,681 of 18,675. Five days held 49.9% of the cancellations in last winter (Dec 2025 to Feb 2026). We hold one winter, and its biggest event, 24 to 27 January 2026, drives most of the result. In summer (Jun–Jul 2026), the five worst days held 31.6%. Summer delayed more flights: 27.9% of departures left 15 or more minutes late in summer (Jun–Jul 2026), against 22.7% in last winter (Dec 2025 to Feb 2026).

One day in January

That Sunday was the worst day of last winter (Dec 2025 to Feb 2026) at 25 of the 31 hubs we track. The next worst days nationally were 26 January (27.1%), 24 January (21.1%) and 23 February (19.7%). Seven days of last winter (Dec 2025 to Feb 2026) had 10% or more of departures cancelled, against one day in summer (Jun–Jul 2026).

BTS records a reason for each cancellation, as the airline reports it, in each airline's own judgment. Across last winter (Dec 2025 to Feb 2026), 81% of cancellations carry BTS's weather code, against 58% in summer (Jun–Jul 2026).

Leaving out the worst days

Taking every day, 2.82% of scheduled departures were cancelled in last winter (Dec 2025 to Feb 2026) and 2.14% in summer (Jun–Jul 2026). That gap is within the day-to-day variation in this data, so it does not separate the two seasons. Leaving out each season's worst days shows where the cancellations sat:

Worst days left out	Last winter (Dec 2025 to Feb 2026)	Summer (Jun–Jul 2026)
3	1.82%	1.76%
5	1.49%	1.59%
10	1.06%	1.22%

We chose this measure after seeing the national figures, which is why the table shows three cut-offs. The median day shows the same shape: 0.74% of departures cancelled in last winter (Dec 2025 to Feb 2026), 1.19% in summer (Jun–Jul 2026).

Why winter cancels in bursts and summer delays build

On 25 January 2026, 8,252 of the 8,681 cancellations carry BTS's weather code, as the airlines recorded it.

BTS's weather category, which airlines also use for cancellations, covers significant meteorological conditions, "actual or forecasted", that in the airline's judgment delay or prevent a flight.

Airlines sometimes cancel flights before a forecast winter storm arrives, and there may be a variety of operational and safety considerations. Our data does not show when each cancellation was decided, so we cannot say how many of those on 25 January were made ahead of the storm.

The FAA's help page on ground delay programs says: "The most common reason for a reduction in acceptance rate is adverse weather such as low ceilings and visibility". A ground delay program controls the number of flights headed to an airport when demand is expected to exceed its acceptance rate for a lengthy period. Our story on thunderstorm days covers those days: hubs cancelled on thunderstorm days.

Summer delays spread across ordinary days

In summer (Jun–Jul 2026), the mean departure delay was 22.3 minutes, against 17.7 minutes in last winter (Dec 2025 to Feb 2026). Summer's share of departures leaving 15 or more minutes late was clearly higher at about 20 of the 31 hubs we track. Last winter's (Dec 2025 to Feb 2026) was higher at Honolulu and, narrowly, Detroit.

What it means for a trip

In last winter's data (Dec 2025 to Feb 2026), the cancellations sat on a few days: five days held about half of the season's cancellations. In summer (Jun–Jul 2026), the delays spread across ordinary days. Cancellations also happened outside December to February: 2.90% of departures were cancelled in March 2026, against 1.55% in December 2025.

GateCast grades possible connections A to F from a year of US flight-delay data. The grade is an estimate. Check your own connection.

About these figures

We hold one December, one January and one February, so last winter (Dec 2025 to Feb 2026) is one winter, and a winter without a late-January storm could look quite different. Summer here means Jun–Jul 2026, the only summer months in the period. Figures cover departures by every US airline that reports to BTS, October 2025 to July 2026; "late" means a departure 15 or more minutes after schedule, among flights that operated. Counts of hubs where one season is "clearly" higher rest on 95% intervals built by resampling days within each season, and move by one between runs, so they are given as "about". Cancellation reasons are reported by the airlines in BTS's categories, in each airline's own judgment. Comments, feedback and corrections to [email protected]. We correct errors on the page.

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