Of 1,862 sampled departures, 39.6% left 15 minutes or more behind schedule. Average lateness was 19.3 minutes. Sample window: Jan 16, 2026 to May 7, 2026.
These are historical aggregates, not live status. A departure is late at 15 minutes past schedule.
| Airline | Flights sampled | Late | Average lateness |
|---|---|---|---|
| Air Transport International Inc. (8C) | 96 | 68.8% | 33.3 min |
| United Airlines (UA) | 93 | 50.5% | 28.5 min |
| Southwest Airlines Co. (WN) | 515 | 47.2% | 23.5 min |
| Alaska Airlines (AS) | 159 | 40.3% | 24.8 min |
| ALS (K4) | 25 | 40.0% | 12.6 min |
39.6% of this ONT sample left 15 minutes late or more.
GET /flight_delays returns the ones that are late at this moment: airline, flight number, scheduled time, actual time and minutes of delay.
Field names match the live API. This flight only shows the shape. It is not a live result.
That URL still says YOUR_ACCESS_KEY.
A 7-day trial replaces it with a real key and returns the ONT departures that are late right now, in the JSON above.
After the trial, Starter is $24.99/mo.
