Seattle–Tacoma International Airport (SEA): Delays & On-Time Performance
Data through May 2026
Seattle–Tacoma International Airport (SEA) in Seattle, WA is a middle-of-the-pack performer: 79% of departures are on time, within a few points of the national 78%. It hosts 11 airlines flying 453 departures a day to 97 destinations, with cancellations at 0.8%.
- Departures on-time
- 79%
- left <15 min late
- Avg dep delay
- 13 min
- Arrivals on-time
- 80%
- Cancelled
- 0.8%
- Destinations
- 97
- nonstop
- Airlines
- 11
Plan your departure from SEA
The choices most likely to improve your odds, based on this airport’s historical record.
- Best departure time
- Around 5 a.m.
- 94% on-time
- Best day to fly
- Tuesday
- 83% on-time
- Cancellation risk
- 0.8%
- below the US average
Monthly on-time trend
Best time of day to depart from SEA
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 78% | 13 min |
| Tuesdaybest | 83% | 10 min |
| Wednesday | 81% | 11 min |
| Thursday | 77% | 13 min |
| Friday | 77% | 14 min |
| Saturday | 80% | 12 min |
| Sunday | 76% | 14 min |
Busiest routes from SEA
Where flights into SEA come from
| Route | Flights/12mo | On-time | Avg delay |
|---|---|---|---|
| LAX (Los Angeles) → SEA | 7,405 | 85% | 10 min |
| PHX (Phoenix) → SEA | 7,317 | 82% | 11 min |
| SFO (San Francisco) → SEA | 6,768 | 76% | 15 min |
| ANC (Anchorage) → SEA | 6,715 | 85% | 10 min |
| DEN (Denver) → SEA | 6,318 | 75% | 16 min |
| LAS (Las Vegas) → SEA | 5,699 | 80% | 13 min |
| ORD (Chicago) → SEA | 5,561 | 72% | 19 min |
| GEG (Spokane) → SEA | 5,280 | 84% | 10 min |
What causes delays at SEA
Share of total delay minutes by cause, as reported by carriers to the US DOT, weighted across routes departing SEA.
- Late-arriving aircraft30%
- Airline operations42%
- National airspace system23%
- Weather5%
Alternative airports near Seattle
Other airports within 120 miles, compared on departure reliability.
| Airport | Distance | On-time departures | Avg delay |
|---|---|---|---|
| PAE — Seattle Paine Field International Airport | 32 mi | 86% | 10 min |
| BLI — Bellingham International Airport | 94 mi | 87% | 10 min |
Compare the airport-level record first, then check the exact route you plan to book.
Airline performance at SEA
| Airline | On-time departures | Avg delay | Flights |
|---|---|---|---|
| SkyWest Airlines | 86% | 9 min | 56,613 |
| United Airlines | 84% | 14 min | 17,982 |
| Envoy Air | 84% | 13 min | 924 |
| Delta Air Lines | 84% | 13 min | 64,040 |
| American Airlines | 77% | 20 min | 12,284 |
| Alaska Airlines | 77% | 12 min | 153,846 |
| Frontier Airlines | 74% | 24 min | 3,107 |
| Spirit Airlines | 74% | 17 min | 1,030 |
| Southwest Airlines | 68% | 17 min | 15,997 |
| Hawaiian Airlines | 64% | 30 min | 2,137 |
| JetBlue Airways | 61% | 34 min | 1,042 |
Frequently asked questions
- How often are flights delayed at SEA?
- 21% of departures from Seattle–Tacoma International Airport left 15+ minutes late between 2024-06 and 2026-05, with an average departure delay of 13 minutes. The national on-time average over the same period was 78%.
- What is the best time of day to depart from SEA?
- Flights scheduled around 5 a.m. depart on time 94% of the time at SEA, versus 66% around 1 a.m.. Booking before noon is the usual rule of thumb here.
- What is the worst month for delays at SEA?
- In this dataset, June 2025 was the weakest month at SEA, with 72% of departures on time.
- How often are flights cancelled at SEA?
- 0.8% of scheduled departures from SEA were cancelled in this period, compared with a national rate of 1.6%.
Popular route pages from this airport
Related guides
Based on 329,002 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.