Historical on-time performance
San Francisco to Seattle
679 miData through May 2026Source: US DOT · BTS
Flights on SFO–SEA arrive on time 73% of the time over the last 12 months.
On-time rate73%arrived within 15 min
p90 delay45 min1 in 10 flights is worse (tail risk)
Cancelled1.2%of scheduled flights
based on 6,765 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Delta Air LinesbestOn-time83%Medianon timep9030 minCancel1.9%Flights894
- United AirlinesOn-time77%Medianon timep9040 minCancel0.3%Flights2,014
- SkyWest AirlinesOn-time74%Medianon timep9040 minCancel1.1%Flights1,110
- Alaska AirlinesOn-time67%Medianon timep9050 minCancel1.6%Flights2,747
Why flights run late
Delay causes
- Airline27%
- Weather3%
- Air traffic (NAS)26%
- Late aircraft45%
- Security0%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline61%
- Weather23%
- Air traffic (NAS)16%
- Security0%
Most cancellations here are attributed to Airline. Shares are among 80 cancellations with a reported cause (BTS reports causes from June 2003).
Over time
On-time trend
By season
On-time rate by month
When to fly
Best time to fly SFO → SEA
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best time of day
Mornings are the most reliable time of day to fly this route — 84% on time.
- Mornings84% on time · p90 20 min · 5,010 flights
- Middays76% on time · p90 45 min · 5,059 flights
- Afternoons73% on time · p90 40 min · 4,036 flights
- Overnights72% on time · p90 50 min · 2,755 flights
- Evenings70% on time · p90 55 min · 3,216 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 72% to 82% on time.
- Tuesdays82% on time · p90 25 min · 2,799 flights
- Saturdays80% on time · p90 30 min · 2,465 flights
- Wednesdays78% on time · p90 40 min · 2,817 flights
- Thursdays75% on time · p90 40 min · 3,013 flights
- Mondays74% on time · p90 45 min · 3,049 flights
- Sundays73% on time · p90 50 min · 2,939 flights
- Fridays72% on time · p90 45 min · 2,994 flights
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