Airports › Washington (IAD) › September 2025
Airport month · September 2025
Washington Dulles International in September 2025
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report.
In September 2025, reporting carriers scheduled 4,815 domestic departures from Washington Dulles International (IAD). 88.5% left less than 15 minutes late and 86.4% reached their destination on time; 0.3% were cancelled.
Nationally that month, 83.1% of flights departed on time and 82.8% arrived on time, so IAD departures were 5.4 points above the national departure figure.
A year earlier, in September 2024, the airport had 4,313 departures with 88.3% leaving on time: a change of +0.2 points, with flights up 12%.
Flights arriving at IAD that month were on time 87.5% of the time (4,811 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 36%, air carrier 33% and national aviation system 29%.
- On time 86.4%
- Arrived 15+ minutes late 13.2%
- Cancelled 0.3%
- Diverted 0.2%
September 2025 against a year earlier, the airport's year and the nation
| Measure | Sep 2025 | Sep 2024 | IAD, 12 months to Jul 2026 | All reported flights, Sep 2025 |
|---|---|---|---|---|
| Departed on time | 88.5% | 88.3% | 82.6% | 83.1% |
| Arrived on time | 86.4% | 86.8% | 80.1% | 82.8% |
| Cancelled | 0.3% | 0.5% | 1.4% | 0.5% |
| Average departure delay (late minutes only) | 9.1 min | 8.7 min | 14.7 min | 12.2 min |
| Scheduled departures a day | 161 | 144 | 159 | 18,748 |
| Scheduled departures | 4,815 | 4,313 | 58,031 | 562,439 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| UA United Airlines | 3,004 | 62% | 85.8% | -1.3 min | 0.1% |
| YX Republic Airline | 834 | 17% | 88.0% | -3.5 min | 0.7% |
| DL Delta Air Lines | 239 | 5% | 86.6% | -1.8 min | 0.0% |
| OO SkyWest Airlines | 158 | 3% | 89.9% | 2.9 min | 0.0% |
| F9 Frontier Airlines | 124 | 3% | 91.1% | -6.1 min | 0.0% |
| AS Alaska Airlines | 120 | 2% | 86.7% | -8.2 min | 0.0% |
| OH PSA Airlines | 115 | 2% | 93.0% | -14.9 min | 0.9% |
| WN Southwest Airlines | 112 | 2% | 75.9% | 5.9 min | 0.0% |
| AA American Airlines | 90 | 2% | 82.2% | 13.7 min | 2.2% |
| G4 Allegiant Air | 19 | 0% | 84.2% | -4.6 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| IAD–ATL | Washington to Atlanta | 315 | 87.9% | 0.6 min | 0.0% |
| IAD–DEN | Washington to Denver | 294 | 84.7% | -1.0 min | 0.0% |
| IAD–SFO | Washington to San Francisco | 206 | 87.4% | -4.4 min | 0.0% |
| IAD–ORD | Washington to Chicago | 203 | 78.8% | 1.5 min | 0.0% |
| IAD–IAH | Washington to Houston | 195 | 92.3% | -8.9 min | 0.0% |
| IAD–DFW | Washington to Dallas/Fort Worth | 185 | 82.2% | 9.1 min | 1.1% |
| IAD–SEA | Washington to Seattle | 179 | 92.2% | -13.1 min | 0.0% |
| IAD–LAX | Washington to Los Angeles | 174 | 89.7% | -7.1 min | 0.6% |
| IAD–MCO | Washington to Orlando | 171 | 90.1% | -3.7 min | 0.0% |
| IAD–CLT | Washington to Charlotte | 164 | 93.9% | -12.6 min | 0.6% |
| IAD–BOS | Washington to Boston | 142 | 57.0% | 23.5 min | 1.4% |
| IAD–RDU | Washington to Raleigh/Durham | 140 | 87.1% | -0.3 min | 0.7% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left IAD on time in September 2025?
88.5% of 4,815 scheduled domestic departures left less than 15 minutes late, and 86.4% reached their destination on time. The national figures that month were 83.1% and 82.8%.
How does that compare with a year earlier?
In September 2024, 88.3% of 4,313 departures left on time and 0.5% were cancelled, against 88.5% and 0.3% in September 2025.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for September 2025; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for IAD · methodology · corrections.