Historical on-time performance
Seattle to Washington
2,306 miData through May 2026Source: US DOT · BTS
Flights on SEA–IAD arrive on time 80% of the time over the last 12 months.
On-time rate80%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled0.7%of scheduled flights
based on 1,844 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- United AirlinesbestOn-time84%Medianon timep9025 minCancel0.6%Flights704
- Alaska AirlinesOn-time78%Medianon timep9035 minCancel0.5%Flights835
- Delta Air LinesOn-time77%Medianon timep9050 minCancel1.3%Flights305
Why flights run late
Delay causes
- Airline43%
- Weather3%
- Air traffic (NAS)15%
- Late aircraft38%
- Security0%
Most delay minutes here are attributed to Airline.
When flights don't go
Why flights were cancelled
- Airline50%
- Weather50%
- Air traffic (NAS)0%
- Security0%
Most cancellations here are attributed to Airline. Shares are among 12 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 SEA → IAD
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best time of day
On-time rates are fairly even by time of day on this route — ranging from 77% to 82% on time.
- Mornings82% on time · p90 25 min · 2,311 flights
- Middays79% on time · p90 30 min · 1,179 flights
- Overnights78% on time · p90 30 min · 1,922 flights
- Afternoons77% on time · p90 35 min · 938 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 76% to 84% on time.
- Wednesdays84% on time · p90 25 min · 882 flights
- Tuesdays83% on time · p90 25 min · 870 flights
- Thursdays80% on time · p90 30 min · 935 flights
- Mondays79% on time · p90 25 min · 929 flights
- Saturdays78% on time · p90 30 min · 855 flights
- Fridays77% on time · p90 35 min · 943 flights
- Sundays76% on time · p90 40 min · 936 flights
Keep exploring