San Francisco (SFO) to Seattle (SEA): On-Time Performance
Data through July 2026
The calendar drives reliability on SFO–SEA. January 2025 flights landed on schedule 88% of the time, but June 2026 dropped to 60% — a gap of 27 points. Across the full period the route averages 75% on-time against a national 78%. Morning departures also hold up better than evening ones (79% vs 69%), which matters most in the rough months.
- On-time
- 75%
- arrived <15 min late
- Avg delay
- 15 min
- completed flights
- Cancelled
- 1.1%
- Flights/day
- 19
- last 12 months
- Duration
- 2h 17m
- scheduled
- Distance
- 679 mi
Best airline from SFO to SEA
4 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 84% | 14 min | 1.2% | 1,764 |
| United Airlines | 78% | 13 min | 0.5% | 4,294 |
| SkyWest Airlines | 75% | 14 min | 0.7% | 2,447 |
| Alaska Airlines | 69% | 17 min | 1.6% | 5,854 |
Monthly on-time trend
Best time to fly from SFO to SEA
Aim for departures around 5 a.m. (96% on-time); avoid 8 a.m. departures (57%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 73% | 16 min |
| Tuesdaybest | 81% | 11 min |
| Wednesday | 76% | 14 min |
| Thursday | 71% | 17 min |
| Friday | 71% | 17 min |
| Saturday | 79% | 13 min |
| Sunday | 72% | 18 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft46%
- Airline operations27%
- National airspace system24%
- Weather4%
Frequently asked questions
- How often are flights from SFO to SEA delayed?
- 26% of SFO–SEA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 15 minutes.
- Which airline is most reliable from SFO to SEA?
- Delta Air Lines has the best on-time record on this route at 84%, based on 1,764 flights. 4 airlines flew SFO–SEA frequently enough to compare in this period.
- What is the best time of day to fly from SFO to SEA?
- Departures around 5 a.m. have the best record (96% on-time), while departures around 8 a.m. have the worst (57%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SFO to SEA?
- The scheduled SFO–SEA flight time averages 2h 17m over 679 miles. Actual arrival times vary — flights on this route land 15+ minutes late 26% of the time.
- How often are SFO to SEA flights cancelled?
- 1.1% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from SFO to SEA?
- June 2026 was the roughest month in this dataset, with only 60% of arrivals on time. The best was January 2025 at 88%. If your dates are flexible, that 27-point gap is worth planning around.
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Based on 14,362 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.