Airports › Seattle (SEA) › March 2026
Airport month · March 2026
Seattle/Tacoma International in March 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 March 2026, reporting carriers scheduled 12,830 domestic departures from Seattle/Tacoma International (SEA). 75.1% left less than 15 minutes late and 78.1% reached their destination on time; 2.2% were cancelled.
Nationally that month, 72.8% of flights departed on time and 73.2% arrived on time, so SEA departures were 2.3 points above the national departure figure.
A year earlier, in March 2025, the airport had 12,577 departures with 82.2% leaving on time: a change of −7.1 points, with flights up 2%.
Flights arriving at SEA that month were on time 75.1% of the time (12,832 scheduled arrivals).
Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 37%, late-arriving aircraft 29% and national aviation system 19%.
- On time 78.1%
- Arrived 15+ minutes late 19.3%
- Cancelled 2.2%
- Diverted 0.3%
March 2026 against a year earlier, the airport's year and the nation
| Measure | Mar 2026 | Mar 2025 | SEA, 12 months to Jul 2026 | All reported flights, Mar 2026 |
|---|---|---|---|---|
| Departed on time | 75.1% | 82.2% | 78.2% | 72.8% |
| Arrived on time | 78.1% | 82.0% | 78.6% | 73.2% |
| Cancelled | 2.2% | 0.4% | 0.9% | 2.9% |
| Average departure delay (late minutes only) | 15.0 min | 10.5 min | 13.2 min | 20.3 min |
| Scheduled departures a day | 428 | 419 | 452 | 20,403 |
| Scheduled departures | 12,830 | 12,577 | 164,821 | 612,102 |
Airlines that month
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| AS Alaska Airlines | 6,169 | 48% | 77.5% | 2.5 min | 1.7% |
| DL Delta Air Lines | 2,596 | 20% | 75.8% | 5.1 min | 3.5% |
| OO SkyWest Airlines | 2,283 | 18% | 82.9% | 3.1 min | 2.3% |
| WN Southwest Airlines | 583 | 5% | 68.8% | 10.2 min | 1.5% |
| UA United Airlines | 561 | 4% | 82.7% | -0.9 min | 1.8% |
| AA American Airlines | 480 | 4% | 81.5% | -2.4 min | 2.9% |
| F9 Frontier Airlines | 98 | 1% | 77.6% | 2.6 min | 5.1% |
| MQ Envoy Air | 60 | 0% | 90.0% | -7.0 min | 0.0% |
Busiest routes that month
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| SEA–PHX | Seattle to Phoenix | 686 | 78.1% | 3.9 min | 2.2% |
| SEA–LAX | Seattle to Los Angeles | 639 | 81.5% | -0.3 min | 2.3% |
| SEA–SFO | Seattle to San Francisco | 528 | 79.7% | 3.9 min | 2.5% |
| SEA–ANC | Seattle to Anchorage | 478 | 66.1% | 16.4 min | 1.0% |
| SEA–LAS | Seattle to Las Vegas | 478 | 74.7% | 5.1 min | 2.7% |
| SEA–DEN | Seattle to Denver | 455 | 77.1% | 4.1 min | 2.6% |
| SEA–GEG | Seattle to Spokane | 418 | 82.8% | 0.8 min | 2.2% |
| SEA–PDX | Seattle to Portland | 397 | 77.6% | 7.8 min | 2.5% |
| SEA–SAN | Seattle to San Diego | 388 | 74.7% | 7.1 min | 1.8% |
| SEA–DFW | Seattle to Dallas/Fort Worth | 386 | 82.4% | -3.7 min | 2.8% |
| SEA–BOI | Seattle to Boise | 369 | 83.5% | 0.7 min | 1.4% |
| SEA–ORD | Seattle to Chicago | 357 | 76.5% | 5.0 min | 2.8% |
By scheduled departure hour
Delay causes
Questions and answers
How many flights left SEA on time in March 2026?
75.1% of 12,830 scheduled domestic departures left less than 15 minutes late, and 78.1% reached their destination on time. The national figures that month were 72.8% and 73.2%.
How does that compare with a year earlier?
In March 2025, 82.2% of 12,577 departures left on time and 0.4% were cancelled, against 75.1% and 2.2% in March 2026.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for March 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.