Why some airlines run late and others do not

Two carriers fly the same routes into the same weather. One arrives on time far more often. The record shows where the difference actually comes from.

Computed from 10,423,751 flights · January 2025 – August 2026 · recalculated whenever new data lands

Across the airlines with enough flights to measure, the gap between the most and least punctual is 8.9 points — Delta Air Lines arrived on time 81.62% of the time, JetBlue Airways only 72.73%. That is not a rounding difference. It is the difference between a flight that usually works and one that usually does not.

The obvious explanation is geography: an airline built around a congested hub inherits that hub's problems. The federal files let that explanation be tested, because carriers must report which of their delay minutes were their own — crew, maintenance, an aircraft arriving late from an earlier leg — and which came from weather or air traffic control.

It does not hold the way you would expect. Carriers reporting most of their delay as their own fault averaged 77.3% on time; those attributing it to weather and airspace averaged 73.1% — 4.2 points worse. The airlines owning their delays are the later ones — which at least means the problem is theirs to fix.

Airline	On time	Cancelled	Own fault	Flights
JetBlue Airways	72.73%	2.56%	70.98%	234,468
Spirit Airlines	73.11%	3.68%	58.9%	134,443
Frontier Airlines	73.21%	1.85%	77.74%	205,332
Allegiant Air	74.1%	0.65%	70.57%	127,163
American Airlines	74.42%	2.3%	80.31%	995,350
PSA Airlines	74.62%	4.34%	78.82%	241,957
Southwest Airlines	76.57%	0.89%	79.16%	1,390,634
Republic Airways	78.49%	4.08%	62.25%	361,482
United Airlines	78.96%	1.02%	62.05%	830,269
SkyWest Airlines	78.97%	1.77%	68.47%	852,935
Alaska Airlines	79.1%	1.28%	70.91%	293,372
Envoy Air	80.22%	2.3%	63.91%	315,435
Hawaiian Airlines	81.45%	0.73%	96.07%	40,187
Delta Air Lines	81.62%	1.62%	74.43%	1,038,728

Airlines by on-time rate, worst first. January 2025 – August 2026.

More analysis

Why your return flight runs later than your outbound The same route, flown the other way, is measurably worse. We checked every route in the record to see how often that holds. The worst month to fly, measured Everyone has a theory about summer storms and Christmas queues. Here is what the flights themselves did, month by month. A cancellation costs you more than a delay — and the airlines differ wildly Cancellation is the outcome that loses you a day and the one that triggers a refund. Some carriers do it five times as often as others.