Airports › Seattle (SEA) › May 2026
Airport month · May 2026
Seattle/Tacoma International in May 2026
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 2026, reporting carriers scheduled 14,564 domestic departures from Seattle/Tacoma International (SEA). 79.8% left less than 15 minutes late and 81.6% reached their destination on time; 0.4% were cancelled.
Nationally that month, 77.1% of flights departed on time and 77.6% arrived on time, so SEA departures were 2.7 points above the national departure figure.
A year earlier, in May 2025, the airport had 14,630 departures with 80.2% leaving on time: a change of −0.4 points, with flights down 0%.
Flights arriving at SEA that month were on time 81.9% of the time (14,569 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 45%, late-arriving aircraft 28% and national aviation system 25%.
- On time 81.6%
- Arrived 15+ minutes late 17.7%
- Cancelled 0.4%
- Diverted 0.3%
May 2026 against a year earlier, the airport's year and the nation
| Measure | May 2026 | May 2025 | SEA, 12 months to Jul 2026 | All reported flights, May 2026 |
|---|---|---|---|---|
| Departed on time | 79.8% | 80.2% | 78.2% | 77.1% |
| Arrived on time | 81.6% | 76.3% | 78.6% | 77.6% |
| Cancelled | 0.4% | 0.4% | 0.9% | 0.9% |
| Average departure delay (late minutes only) | 11.6 min | 11.0 min | 13.2 min | 16.0 min |
| Scheduled departures a day | 486 | 488 | 452 | 20,391 |
| Scheduled departures | 14,564 | 14,630 | 164,821 | 611,735 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| AS Alaska Airlines | 6,823 | 47% | 82.4% | -3.1 min | 0.4% |
| DL Delta Air Lines | 2,857 | 20% | 82.1% | 0.9 min | 0.6% |
| OO SkyWest Airlines | 2,577 | 18% | 86.1% | -1.1 min | 0.0% |
| UA United Airlines | 816 | 6% | 74.0% | 6.1 min | 0.7% |
| AA American Airlines | 630 | 4% | 74.8% | 7.1 min | 1.1% |
| WN Southwest Airlines | 610 | 4% | 69.8% | 8.5 min | 0.3% |
| MQ Envoy Air | 114 | 1% | 80.7% | 5.5 min | 0.0% |
| F9 Frontier Airlines | 100 | 1% | 87.0% | 3.8 min | 0.0% |
| B6 JetBlue Airways | 37 | 0% | 51.4% | 13.7 min | 2.7% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| SEA–LAX | Seattle to Los Angeles | 677 | 86.7% | -3.4 min | 0.1% |
| SEA–PHX | Seattle to Phoenix | 623 | 82.3% | -0.6 min | 0.3% |
| SEA–SFO | Seattle to San Francisco | 591 | 40.1% | 30.7 min | 1.4% |
| SEA–ANC | Seattle to Anchorage | 587 | 79.0% | 2.6 min | 0.2% |
| SEA–ORD | Seattle to Chicago | 562 | 80.6% | 1.1 min | 0.0% |
| SEA–DEN | Seattle to Denver | 546 | 82.4% | -2.6 min | 0.2% |
| SEA–LAS | Seattle to Las Vegas | 497 | 78.1% | 5.9 min | 0.8% |
| SEA–DFW | Seattle to Dallas/Fort Worth | 482 | 74.9% | 2.6 min | 1.5% |
| SEA–SAN | Seattle to San Diego | 427 | 82.4% | -2.0 min | 0.9% |
| SEA–GEG | Seattle to Spokane | 414 | 87.9% | -1.5 min | 0.2% |
| SEA–PDX | Seattle to Portland | 391 | 84.4% | 0.9 min | 0.0% |
| SEA–SMF | Seattle to Sacramento | 389 | 85.1% | -1.3 min | 0.0% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left SEA on time in May 2026?
79.8% of 14,564 scheduled domestic departures left less than 15 minutes late, and 81.6% reached their destination on time. The national figures that month were 77.1% and 77.6%.
How does that compare with a year earlier?
In May 2025, 80.2% of 14,630 departures left on time and 0.4% were cancelled, against 79.8% and 0.4% in May 2026.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for May 2026; 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.