Airports › Washington (IAD) › May 2025
Airport month · May 2025
Washington Dulles International in May 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 May 2025, reporting carriers scheduled 5,491 domestic departures from Washington Dulles International (IAD). 80.2% left less than 15 minutes late and 73.4% reached their destination on time; 0.6% were cancelled.
Nationally that month, 76.7% of flights departed on time and 75.4% arrived on time, so IAD departures were 3.5 points above the national departure figure.
A year earlier, in May 2024, the airport had 4,648 departures with 81.8% leaving on time: a change of −1.6 points, with flights up 18%.
Flights arriving at IAD that month were on time 78.5% of the time (5,498 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, national aviation system 36%, air carrier 27% and late-arriving aircraft 22%.
- On time 73.4%
- Arrived 15+ minutes late 25.8%
- Cancelled 0.6%
- Diverted 0.2%
May 2025 against a year earlier, the airport's year and the nation
| Measure | May 2025 | May 2024 | IAD, 12 months to Jul 2026 | All reported flights, May 2025 |
|---|---|---|---|---|
| Departed on time | 80.2% | 81.8% | 82.6% | 76.7% |
| Arrived on time | 73.4% | 76.9% | 80.1% | 75.4% |
| Cancelled | 0.6% | 0.6% | 1.4% | 1.0% |
| Average departure delay (late minutes only) | 16.5 min | 15.4 min | 14.7 min | 17.5 min |
| Scheduled departures a day | 183 | 155 | 159 | 20,188 |
| Scheduled departures | 5,491 | 4,648 | 58,031 | 605,648 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| UA United Airlines | 3,310 | 60% | 72.1% | 12.2 min | 0.3% |
| YX Republic Airline | 958 | 17% | 78.2% | 10.5 min | 1.3% |
| OO SkyWest Airlines | 269 | 5% | 81.8% | 8.7 min | 0.0% |
| DL Delta Air Lines | 260 | 5% | 75.0% | 14.2 min | 0.4% |
| AS Alaska Airlines | 209 | 4% | 78.5% | -1.5 min | 0.0% |
| OH PSA Airlines | 146 | 3% | 68.5% | 16.6 min | 3.4% |
| F9 Frontier Airlines | 132 | 2% | 56.1% | 25.5 min | 1.5% |
| WN Southwest Airlines | 114 | 2% | 74.6% | 8.8 min | 0.0% |
| AA American Airlines | 61 | 1% | 57.4% | 12.1 min | 3.3% |
| G4 Allegiant Air | 32 | 1% | 68.8% | 20.8 min | 3.1% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| IAD–ATL | Washington to Atlanta | 349 | 66.2% | 24.0 min | 0.6% |
| IAD–DEN | Washington to Denver | 311 | 74.6% | 8.7 min | 0.3% |
| IAD–SFO | Washington to San Francisco | 273 | 77.7% | 0.7 min | 0.4% |
| IAD–LAX | Washington to Los Angeles | 254 | 81.5% | -0.9 min | 0.0% |
| IAD–MCO | Washington to Orlando | 206 | 63.1% | 19.8 min | 0.0% |
| IAD–SEA | Washington to Seattle | 203 | 83.7% | -3.7 min | 0.0% |
| IAD–CLT | Washington to Charlotte | 198 | 68.2% | 15.3 min | 3.5% |
| IAD–IAH | Washington to Houston | 186 | 68.8% | 15.6 min | 0.5% |
| IAD–ORD | Washington to Chicago | 186 | 73.1% | 10.4 min | 0.0% |
| IAD–DFW | Washington to Dallas/Fort Worth | 158 | 59.5% | 19.6 min | 1.3% |
| IAD–BOS | Washington to Boston | 155 | 61.9% | 23.7 min | 0.0% |
| IAD–EWR | Washington to Newark | 144 | 31.3% | 74.9 min | 4.9% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left IAD on time in May 2025?
80.2% of 5,491 scheduled domestic departures left less than 15 minutes late, and 73.4% reached their destination on time. The national figures that month were 76.7% and 75.4%.
How does that compare with a year earlier?
In May 2024, 81.8% of 4,648 departures left on time and 0.6% were cancelled, against 80.2% and 0.6% in May 2025.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for May 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.