Airports › Seattle (SEA) › April 2026
Airport month · April 2026
Seattle/Tacoma International in April 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 April 2026, reporting carriers scheduled 12,864 domestic departures from Seattle/Tacoma International (SEA). 84.4% left less than 15 minutes late and 85.3% reached their destination on time; 0.2% were cancelled.
Nationally that month, 79.1% of flights departed on time and 78.9% arrived on time, so SEA departures were 5.3 points above the national departure figure.
A year earlier, in April 2025, the airport had 12,716 departures with 83.0% leaving on time: a change of +1.4 points, with flights up 1%.
Flights arriving at SEA that month were on time 85.1% of the time (12,867 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 53%, national aviation system 25% and late-arriving aircraft 19%.
- On time 85.3%
- Arrived 15+ minutes late 14.4%
- Cancelled 0.2%
- Diverted 0.2%
April 2026 against a year earlier, the airport's year and the nation
| Measure | Apr 2026 | Apr 2025 | SEA, 12 months to Jul 2026 | All reported flights, Apr 2026 |
|---|---|---|---|---|
| Departed on time | 84.4% | 83.0% | 78.2% | 79.1% |
| Arrived on time | 85.3% | 81.7% | 78.6% | 78.9% |
| Cancelled | 0.2% | 0.2% | 0.9% | 0.9% |
| Average departure delay (late minutes only) | 9.7 min | 9.7 min | 13.2 min | 14.5 min |
| Scheduled departures a day | 429 | 424 | 452 | 19,931 |
| Scheduled departures | 12,864 | 12,716 | 164,821 | 597,919 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| AS Alaska Airlines | 6,097 | 47% | 86.4% | -5.1 min | 0.1% |
| DL Delta Air Lines | 2,662 | 21% | 84.6% | 2.2 min | 0.3% |
| OO SkyWest Airlines | 2,147 | 17% | 89.1% | -4.2 min | 0.0% |
| UA United Airlines | 628 | 5% | 78.0% | 1.5 min | 0.2% |
| WN Southwest Airlines | 588 | 5% | 73.5% | 9.3 min | 0.2% |
| AA American Airlines | 564 | 4% | 82.3% | 5.9 min | 0.9% |
| F9 Frontier Airlines | 99 | 1% | 72.7% | 7.3 min | 2.0% |
| MQ Envoy Air | 79 | 1% | 96.2% | -10.6 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| SEA–PHX | Seattle to Phoenix | 665 | 85.7% | -1.1 min | 0.2% |
| SEA–LAX | Seattle to Los Angeles | 611 | 89.0% | -4.9 min | 0.5% |
| SEA–SFO | Seattle to San Francisco | 495 | 48.5% | 23.1 min | 0.0% |
| SEA–LAS | Seattle to Las Vegas | 476 | 84.0% | -0.7 min | 0.2% |
| SEA–DEN | Seattle to Denver | 470 | 87.4% | -4.0 min | 0.2% |
| SEA–ORD | Seattle to Chicago | 465 | 77.8% | 6.5 min | 1.1% |
| SEA–ANC | Seattle to Anchorage | 452 | 84.1% | -0.3 min | 0.0% |
| SEA–DFW | Seattle to Dallas/Fort Worth | 414 | 83.6% | 5.7 min | 0.7% |
| SEA–SAN | Seattle to San Diego | 409 | 88.0% | -3.5 min | 0.0% |
| SEA–GEG | Seattle to Spokane | 386 | 86.0% | -3.7 min | 0.0% |
| SEA–PDX | Seattle to Portland | 374 | 90.4% | -3.4 min | 0.3% |
| SEA–SMF | Seattle to Sacramento | 369 | 87.5% | -3.0 min | 0.0% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left SEA on time in April 2026?
84.4% of 12,864 scheduled domestic departures left less than 15 minutes late, and 85.3% reached their destination on time. The national figures that month were 79.1% and 78.9%.
How does that compare with a year earlier?
In April 2025, 83.0% of 12,716 departures left on time and 0.2% were cancelled, against 84.4% and 0.2% in April 2026.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for April 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.