Historical on-time performance
Washington to San Diego
2,253 miData through May 2026Source: US DOT · BTS
Flights on IAD–SAN arrive on time 83% of the time over the last 12 months.
On-time rate83%arrived within 15 min
p90 delay30 min1 in 10 flights is worse (tail risk)
Cancelled0.4%of scheduled flights
based on 1,345 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- United AirlinesbestOn-time86%Medianon timep9020 minCancel0.4%Flights1,040
- Alaska AirlinesOn-time71%Medianon timep9050 minCancel0.7%Flights305
Why flights run late
Delay causes
- Airline20%
- Weather16%
- Air traffic (NAS)33%
- Late aircraft31%
- Security0%
Most delay minutes here are attributed to Air traffic (NAS).
When flights don't go
Why flights were cancelled
- Airline33%
- Weather67%
- Air traffic (NAS)0%
- Security0%
Most cancellations here are attributed to Weather. Shares are among 6 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 IAD → SAN
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 — 90% on time.
- Mornings90% on time · p90 10 min · 1,385 flights
- Middays87% on time · p90 20 min · 1,248 flights
- Afternoons78% on time · p90 30 min · 210 flights
- Evenings73% on time · p90 45 min · 1,776 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 80% to 85% on time.
- Tuesdays85% on time · p90 25 min · 657 flights
- Mondays84% on time · p90 25 min · 668 flights
- Saturdays82% on time · p90 30 min · 635 flights
- Fridays81% on time · p90 30 min · 673 flights
- Wednesdays81% on time · p90 30 min · 657 flights
- Sundays80% on time · p90 35 min · 663 flights
- Thursdays80% on time · p90 25 min · 666 flights
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