Of 2,131 sampled Y4 departures, 42.2% left 15 minutes or more behind schedule. Average lateness was 19.2 minutes. Sample window: Nov 4, 2025 to Oct 29, 2026.
These are historical aggregates, not live status. A departure is late at 15 minutes past schedule.
| Month | Departures sampled | Late | Average lateness |
|---|---|---|---|
| Nov 2025 | 29 | 44.8% | 37.8 min |
| Jan 2026 | 329 | 35.6% | 15.7 min |
| Mar 2026 | 785 | 34.1% | 16.8 min |
| May 2026 | 222 | 45.5% | 17.0 min |
| Jun 2026 | 68 | 63.2% | 26.9 min |
| Jul 2026 | 195 | 47.2% | 23.6 min |
| Aug 2026 | 177 | 43.5% | 21.8 min |
| Sep 2026 | 158 | 44.3% | 18.1 min |
| Oct 2026 | 147 | 73.5% | 27.3 min |
| Departure airport | Departures sampled | Late | Average lateness |
|---|---|---|---|
| Los Angeles International Airport (LAX) | 927 | 48.9% | 21.6 min |
| Oakland San Francisco Bay Airport (OAK) | 184 | 15.2% | 5.9 min |
| Chicago Midway International Airport (MDW) | 133 | 55.6% | 29.8 min |
| Harry Reid International Airport (LAS) | 100 | 44.0% | 18.0 min |
| Dallas Fort Worth International Airport (DFW) | 93 | 36.6% | 15.7 min |
| Denver International Airport (DEN) | 83 | 51.8% | 24.5 min |
| San Antonio International Airport (SAT) | 81 | 14.8% | 10.1 min |
| Mineta San Jose International Airport (SJC) | 72 | 6.9% | 0.9 min |
| George Bush Intercontinental Airport (IAH) | 67 | 67.2% | 37.9 min |
| Ontario International Airport (ONT) | 63 | 23.8% | 8.7 min |
GET /flight_delays filtered by airline_iata=Y4 returns the flights delayed at this moment: flight number, scheduled and actual times and minutes of delay.
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