Which Months Cancel the Most Flights

Summary

1.48% of scheduled departures at covered airports were cancelled. January was the worst calendar month at 3.78% and October the best at 0.62%. January, July and August held 48.6% of cancellations on 27.4% of flights. January is also the worst month at 52 of 63 airports.

Across 64 covered airports, 1.48% of scheduled departures were cancelled. January had the highest rate, 3.78% (50,743 of 1,343,722 flights, 3 years pooled), and October the lowest, 0.62%, which makes the worst month 6.1 times the best. The three months with the highest rates, January, July and August, held 27.4% of scheduled flights and 48.6% of cancellations.

All covered airports and every year in the data for the month together, so a month that appears in more years has more flights. The rate is cancelled flights over scheduled flights, counted at the departure airport. Share of cancellations is the month’s part of all cancelled flights in the data.

January pools 3 years. With 2026, its worst, taken out, the rate is 3.35%, against 3.78% with it. That is still above October, the lowest month, at 0.62%.

Each year and month on its own, all covered airports together. The lowest was November 2023, at 0.13%.

Covered airports with at least 5,000 scheduled departures and at least 1,000 in every calendar month, ordered by the rate in their worst month. 1 airport is left out for want of flights. Every year in the data pooled.

Airports with the highest-rate month tied are placed in the earlier month of the year.

January, the worst month for the network, is the worst month at 52 of 63 airports. January is the worst month at 52. The airports with the highest single-month rates are the ones with a bad month rather than a bad year: DCA reached 8.18% in January against 2.95% over all months.

A cancellation rate describes flights the airline scheduled and did not operate. It does not say whether the passenger was rebooked, or whether the cancellation was announced the day before or at the gate. The data runs from July 2023 to July 2026. The months pool its years, so a month that falls in more of them has more flights and one bad year weighs less in it. A month with the highest rate is a month in which more scheduled flights were cancelled; the data does not say why, and one year’s pattern is not a forecast for the next. The three worst months hold more of the cancellations than their share of the flights. The report on why airlines cancel splits the coded causes.