Airports › Seattle (SEA) › August 2025
Airport month · August 2025
Seattle/Tacoma International in August 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 August 2025, reporting carriers scheduled 15,970 domestic departures from Seattle/Tacoma International (SEA). 74.7% left less than 15 minutes late and 72.8% reached their destination on time; 0.7% were cancelled.
Nationally that month, 76.8% of flights departed on time and 76.3% arrived on time, so SEA departures were 2.1 points below the national departure figure.
A year earlier, in August 2024, the airport had 15,984 departures with 74.9% leaving on time: a change of −0.2 points, with flights down 0%.
Flights arriving at SEA that month were on time 75.2% of the time (15,976 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 42%, late-arriving aircraft 36% and national aviation system 20%.
- On time 72.8%
- Arrived 15+ minutes late 26.2%
- Cancelled 0.7%
- Diverted 0.3%
August 2025 against a year earlier, the airport's year and the nation
| Measure | Aug 2025 | Aug 2024 | SEA, 12 months to Jul 2026 | All reported flights, Aug 2025 |
|---|---|---|---|---|
| Departed on time | 74.7% | 74.9% | 78.2% | 76.8% |
| Arrived on time | 72.8% | 72.0% | 78.6% | 76.3% |
| Cancelled | 0.7% | 0.8% | 0.9% | 1.1% |
| Average departure delay (late minutes only) | 14.4 min | 14.6 min | 13.2 min | 17.6 min |
| Scheduled departures a day | 532 | 533 | 452 | 20,079 |
| Scheduled departures | 15,970 | 15,984 | 164,821 | 602,378 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| AS Alaska Airlines | 7,258 | 45% | 66.3% | 11.4 min | 0.9% |
| DL Delta Air Lines | 2,919 | 18% | 81.0% | 3.2 min | 0.3% |
| OO SkyWest Airlines | 2,757 | 17% | 86.2% | 0.1 min | 0.0% |
| UA United Airlines | 972 | 6% | 73.9% | 13.4 min | 0.7% |
| WN Southwest Airlines | 898 | 6% | 64.6% | 13.4 min | 0.0% |
| AA American Airlines | 626 | 4% | 68.7% | 16.2 min | 2.7% |
| HA Hawaiian Airlines | 205 | 1% | 55.6% | 27.6 min | 0.5% |
| F9 Frontier Airlines | 162 | 1% | 71.6% | 21.3 min | 1.2% |
| B6 JetBlue Airways | 93 | 1% | 65.6% | 29.8 min | 0.0% |
| MQ Envoy Air | 68 | 0% | 85.3% | -5.5 min | 0.0% |
| NK Spirit Airlines | 12 | 0% | 66.7% | 14.8 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| SEA–ANC | Seattle to Anchorage | 724 | 71.5% | 7.0 min | 1.1% |
| SEA–DEN | Seattle to Denver | 644 | 64.4% | 15.8 min | 0.8% |
| SEA–LAX | Seattle to Los Angeles | 635 | 79.8% | 4.6 min | 0.5% |
| SEA–SFO | Seattle to San Francisco | 619 | 73.2% | 11.9 min | 0.6% |
| SEA–ORD | Seattle to Chicago | 599 | 58.9% | 23.2 min | 1.7% |
| SEA–PHX | Seattle to Phoenix | 585 | 74.5% | 7.0 min | 0.3% |
| SEA–GEG | Seattle to Spokane | 513 | 73.9% | 6.8 min | 0.6% |
| SEA–LAS | Seattle to Las Vegas | 487 | 74.7% | 6.1 min | 0.0% |
| SEA–DFW | Seattle to Dallas/Fort Worth | 476 | 69.7% | 14.4 min | 2.7% |
| SEA–SMF | Seattle to Sacramento | 427 | 77.3% | 5.8 min | 0.2% |
| SEA–SAN | Seattle to San Diego | 426 | 71.1% | 8.0 min | 1.6% |
| SEA–PDX | Seattle to Portland | 416 | 81.7% | 3.2 min | 0.0% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left SEA on time in August 2025?
74.7% of 15,970 scheduled domestic departures left less than 15 minutes late, and 72.8% reached their destination on time. The national figures that month were 76.8% and 76.3%.
How does that compare with a year earlier?
In August 2024, 74.9% of 15,984 departures left on time and 0.8% were cancelled, against 74.7% and 0.7% in August 2025.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for August 2025; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for SEA · methodology · corrections.