Seasonal Flight Delay Patterns
Average monthly performance across 2019-2025 — 44,648,013 flights
Best Month to Fly
September
85.2% on-time rate — Avg delay 10.2 min
Worst Month to Fly
July
75.7% on-time rate — Avg delay 18.4 min
On-Time Rate by Month (Average 2019-2025)
Monthly Averages
| Month | Avg Flights | On-Time | Avg Delay | Cancel % |
|---|---|---|---|---|
| January | 530,931 | 80.3% | 13.0 min | 2.8% |
| February | 488,217 | 81.2% | 12.4 min | 2.5% |
| March | 580,370 | 79.9% | 12.3 min | 3.6% |
| April | 522,874 | 77.2% | 11.9 min | 7.1% |
| May | 526,674 | 80.7% | 13.4 min | 2.0% |
| June | 540,543 | 76.6% | 17.1 min | 1.7% |
| July | 579,720 | 75.7% | 18.4 min | 2.0% |
| August | 575,508 | 79.1% | 15.0 min | 1.8% |
| September | 534,181 | 85.2% | 10.2 min | 1.1% |
| October | 563,643 | 84.4% | 10.5 min | 0.9% |
| November | 538,646 | 84.9% | 10.3 min | 0.9% |
| December | 544,513 | 79.6% | 14.1 min | 1.8% |
Data source: Bureau of Transportation Statistics (BTS) On-Time Performance dataset. Statistics are based on reported flight data from 2019-2025. See our data methodology for details.