What 26 Million US Flights Say About Delays

We put the US government's airline on-time records into a free tool, the Flight Delay Explorer, and looked for patterns. Most of what we found is useful to know. A couple of the results are silly on purpose.

Data through June 2026. About 26 million flights, January 2023 to June 2026.

What counts as delayed

The numbers come from the US Department of Transportation's Bureau of Transportation Statistics, which collects on-time records from the larger US airlines. A flight counts as delayed when it arrived at the gate 15 minutes or more after its scheduled time. That is the government's definition, not ours.

Across all of those flights, 20.8% were delayed. Keep that number in mind when reading the rest.

The findings

Each row links to the explorer with that filter already applied, so you can check the number or add filters of your own. Times are scheduled local times, taken from the airlines' own schedules.

Filter	Delayed	Matching flights
Scheduled to arrive 1:00 to 1:59 a.m.	35.9%	54,825
Scheduled to depart 7:00 to 7:59 p.m.	29.7%	1,319,043
Flying in July	27.9%	2,011,851
Flying on a Sunday	23.3%	3,911,926
Origin airport code contains W	23.3%	2,965,746
Origin airport code contains Q	18.2%	167,673
Flying on a Tuesday	17.7%	3,622,731
Flying in November	16.0%	1,844,599
Scheduled to depart 5:00 to 5:59 a.m.	8.8%	650,375
Even flight numbers	20.8%	13,233,933
Odd flight numbers	20.8%	13,185,448

Late flights were delayed more than early ones

Of flights scheduled to arrive between 1:00 and 1:59 a.m., 35.9% were delayed. That is a small group, 54,825 flights. The much larger group of flights scheduled to leave between 7:00 and 7:59 p.m. did not do much better, at 29.7%.

At the other end of the day, only 8.8% of flights scheduled to leave between 5:00 and 5:59 a.m. were delayed. If you can face the alarm clock, the early flight has the best record in this table.

July is rough, November is calm

July flights were delayed 27.9% of the time. November flights were delayed 16.0% of the time. Across the week, Sunday came in at 23.3% and Tuesday at 17.7%.

The data shows when delays happened. It does not say why they happened.

Airports with a Q in the code

Flights leaving an airport whose code contains a W were delayed 23.3% of the time. For codes that contain a Q, it was 18.2%.

This one is a joke, and we included it on purpose. The letters in an airport's code have nothing to do with how the airport is run. Any filter you pick splits flights into groups, and those groups end up with different numbers even when the filter means nothing. It is a good reminder to be careful with the other rows too.

Even and odd flight numbers

Even-numbered flights: 20.8% delayed, across 13,233,933 flights. Odd-numbered flights: 20.8% delayed, across 13,185,448 flights.

Yes, they are the same, and both match the overall rate. Whether a flight number is even or odd has nothing to do with delays, and the data agrees.

Your flight is not an average

Every number above is an average over years of flights. None of them can tell you what will happen to the flight you are taking tomorrow. A July flight can leave on time on a clear day, and a 5 a.m. departure can still sit at the gate if a storm is heading for the airport it is flying to.

That is what FlightForecasts is for. We look at the weather, air traffic control plans and the schedule of the aircraft flying your trip, and email you a plain-English forecast for your flight before you fly. You can try it on a real flight without making an account.

Get a free forecast for your flight

Try your own filters

The Flight Delay Explorer is free and has no sign-up. Pick a month, a day of the week or a time of day and see what share of matching flights were delayed. Every view has its own link, so you can share what you find.