Of 3,082 sampled 4Y departures, 86.3% left 15 minutes or more behind schedule. Average lateness was 35.4 minutes. Sample window: Nov 3, 2025 to Oct 31, 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 | 150 | 74.0% | 27.8 min |
| Dec 2025 | 134 | 83.6% | 41.4 min |
| Jan 2026 | 44 | 43.2% | 19.5 min |
| Feb 2026 | 33 | 0.0% | 1.4 min |
| Mar 2026 | 85 | 52.9% | 25.8 min |
| Apr 2026 | 42 | 2.4% | 3.2 min |
| May 2026 | 118 | 72.0% | 24.3 min |
| Jun 2026 | 225 | 96.0% | 39.8 min |
| Jul 2026 | 565 | 94.3% | 37.6 min |
| Aug 2026 | 574 | 92.2% | 39.4 min |
| Sep 2026 | 577 | 91.3% | 36.4 min |
| Oct 2026 | 535 | 89.9% | 36.5 min |
| Departure airport | Departures sampled | Late | Average lateness |
|---|---|---|---|
| Frankfurt Main Airport (FRA) | 2,501 | 95.2% | 38.9 min |
| Toulouse-Blagnac Airport (TLS) | 380 | 33.4% | 14.7 min |
| Orlando International Airport (MCO) | 36 | 86.1% | 39.0 min |
| Munich Airport (MUC) | 36 | 80.6% | 26.2 min |
| Nantes Atlantique Airport (NTE) | 24 | 20.8% | 9.9 min |
| Tampa International Airport (TPA) | 22 | 86.4% | 39.1 min |
GET /flight_delays filtered by airline_iata=4Y returns the flights delayed at this moment: flight number, scheduled and actual times and minutes of delay.
That URL still says YOUR_ACCESS_KEY.
A 7-day trial replaces it with a real key. After the trial, Starter is $24.99/mo.
