Guide
How late do late flights run? The long tail of US delays
77.3% of US flights arrive on time, yet 36.6% of late ones run an hour or more behind and the average late flight lands 73 minutes late. By airline and airport.
Most US flights are not late. Over September 2025 to August 2026, 77.3% of completed flights reached the gate less than 15 minutes after schedule, and the median flight in the file arrived a few minutes early. Airlines pad their schedules, and on a normal day the padding wins.
The flights that do run late tell a different story. 36.6% of them arrived an hour or more behind. The average late flight landed 73 minutes after its scheduled time. That figure is longer than the hour mark itself, which tells you the late side of the distribution is not a gentle slope.
It is a long tail, and that tail is what breaks trips.
Why delay has a long tail
A flight can only be early by so much. Push back on time, catch a tailwind, and you might beat the schedule by 20 minutes. There is no equivalent limit on the other side. A mechanical problem that needs a part flown in, a crew that runs out of legal duty hours, a ground delay programme that assigns a two-hour wait: each can turn one departure into a three-hour delay, and each happens often enough to move an average.
Delay also compounds. The DOT's cause data charges 40% of all delay minutes nationally to late-arriving aircraft, meaning the plane was already behind when it reached the gate. A 40-minute problem in the morning does not stay 40 minutes if the aircraft has four more legs to fly and short turns between them, and a crew delayed on one leg can time out before the last one, forcing the airline to find a reserve crew or wait.
The 15-minute rule hides all of this. A flight that lands 16 minutes late and one that lands four hours late count as the same single late flight in an on-time rate. Two airlines with identical on-time rates can deliver very different days to the passengers on their late flights.
Airlines: the on-time rank and the tail rank disagree
US average 36.6%
0.0%50.0%
Late means arriving 15 minutes or more behind schedule. The dashed line is the US figure. Source: US DOT Bureau of Transportation Statistics, September 2025 to August 2026.
The widest gap between an airline's punctuality and its tail sits with the regional carriers. SkyWest Airlines ran 78.7% on time, against 77.3% nationally. But 42.3% of its late flights ran an hour or more behind, and its average late flight landed 88 minutes late. PSA Airlines, which flies American Eagle routes, averaged 96 minutes per late flight, at or near the top of the table.
Southwest Airlines runs the opposite profile. Its on-time rate was 75.7%, below SkyWest's 78.7%, but only 27.6% of its late flights ran an hour or more, and its average late flight landed 53 minutes behind. Southwest is often a little late and rarely very late. SkyWest is usually on time and, when it is not, often badly late.
US average 73 min
0 min100 min
Averaged over flights arriving 15 minutes or more behind schedule only. Source: US DOT Bureau of Transportation Statistics, September 2025 to August 2026.
The regional tail is consistent with how regional flying works. A regional carrier operates small jets for a mainline partner, often into outstations with one or two flights a day, no spare aircraft and no maintenance base. When an aircraft breaks there, the next flight waits for a part or a mechanic to arrive. During a ground delay programme, airlines can also swap arrival slots among their own flights, and they tend to protect the larger mainline aircraft carrying more passengers, which pushes the delay onto the regional flights. Not every regional carrier fits the pattern: Envoy Air's average late flight ran 70 minutes, close to the national figure.
Allegiant Air is a different case with a similar result. Its average late flight ran 88 minutes behind. Allegiant flies leisure routes between small cities a few times a week, so when an aircraft goes out of service there is rarely another one nearby to substitute. Southwest's short delays fit the opposite structure: dense schedules, short sectors and large bases with spare aircraft.
Alaska Airlines (52 minutes) and Hawaiian Airlines (57 minutes) sit at the short end with Southwest. Hawaiian's schedule is dominated by short inter-island hops within a closed network, the purest version of that low-tail structure. One caveat on both: Hawaiian is reported under its own code only from August to December 2025, and from January 2026 the same flights, inter-island included, appear under Alaska's code. I noticed it when the Honolulu to Kahului route split into two carrier files, and it means Alaska's figure now carries some of Hawaii's short hops.
Airports: where the hour-plus delays land
US average 8.3%
0.0%15.0%
Departures from each airport, measured on arrival at the destination. Source: US DOT Bureau of Transportation Statistics, September 2025 to August 2026.
Airport figures cover departures, measured at the gate at the other end. By that measure, the share of all departures arriving an hour or more late ranges from 3.7% at Kahului (OGG) to 12.1% at Chicago (ORD), with a median of 7.8% across the 60 airports. The top of the list is the congested hubs and South Florida: O'Hare at 12.1%, Fort Lauderdale at 11.5%, LaGuardia and Washington National at 11.5% and 11.4%.
The average delay tells a slightly different story. The longest average late arrivals come from mid-sized airports, not the big hubs: Charleston (CHS) at 85.6 minutes, Jacksonville (JAX) at 84.6. Charleston runs 78.9% on time, better than the national figure, but when one of its flights is late it tends to be very late. That is consistent with a spoke airport served largely by aircraft arriving from hubs, with few spare aircraft or crews on site and fewer later flights to rebook onto.
US average 73 min
0 min90 min
Averaged over departures arriving 15 minutes or more behind schedule only. Source: US DOT Bureau of Transportation Statistics, September 2025 to August 2026.
Oakland (50 minutes), Hobby (53) and San Jose (52), all airports where Southwest flies much of the schedule, sit at the short end with the Hawaiian airports.
Why the tail matters more than the average
A connection does not fail on the average flight. It fails on the one that runs past your buffer.
Say you have 60 minutes to connect, and you need about 30 of them to walk to the next gate and board. Your inbound flight can arrive up to about half an hour late and you still make it. The on-time rate tells you how often the inbound arrives within 15 minutes, which is not quite the question. The share of flights arriving an hour or more late tells you how often the connection is certainly gone.
That is where the tail changes the choice. SkyWest's higher on-time rate did not translate into fewer blown connections: 9.0% of its flights arrived an hour or more late, against 6.7% for Southwest. The tail more than cancelled the on-time advantage. If my inbound leg were a SkyWest flight into a hub, I would leave the buffer I would leave for a much less punctual airline.
These figures also leave something out. Cancelled and diverted flights have no arrival at the scheduled gate, and I excluded both from every delay figure here (a flight that turns back to its departure airport counts as a diversion in the file), so the most disruptive outcome of all sits outside the tail. An airline that cancels rather than runs a flight five hours late can look better on average delay than one that does the opposite.
How I use the tail before booking
For a connection, compare the hour-late share, not the on-time rate. It is the figure that predicts a missed connection.
On a regional leg, add buffer. If the first leg of your trip is a regional flight into a hub, the tail is long even when the on-time rate looks good. The connecting flight buffer guide sets out how much time to leave.
Check your specific connection. The connection risk tool estimates the chance of missing a connection from the arrival-delay distribution of the actual inbound route, which is the tail rather than the average.
Keep both legs on one ticket. When the tail catches you, the airline has to rebook you if the connection was on the same booking. On separate tickets, it does not.
See the tail for your trip: SkyWest (OO) · Southwest · PSA (OH) · Charleston (CHS) · Connection risk tool · Missed connections at major hubs