Historical on-time performance
San Jose to Ontario
334 miData through May 2026Source: US DOT · BTS
Flights on SJC–ONT arrive on time 84% of the time over the last 12 months.
On-time rate84%arrived within 15 min
p90 delay25 min1 in 10 flights is worse (tail risk)
Cancelled0.0%of scheduled flights
based on 1,317 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Southwest AirlinesOn-time84%Medianon timep9025 minCancel0.0%Flights1,317
Why flights run late
Delay causes
- Airline29%
- Weather0%
- Air traffic (NAS)4%
- Late aircraft67%
- Security0%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline73%
- Weather23%
- Air traffic (NAS)3%
- Security0%
Most cancellations here are attributed to Airline. Shares are among 60 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 SJC → ONT
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 — 96% on time.
- Mornings96% on time · p90 on time · 1,193 flights
- Middays90% on time · p90 15 min · 965 flights
- Afternoons83% on time · p90 25 min · 533 flights
- Evenings79% on time · p90 35 min · 813 flights
- Overnights69% on time · p90 65 min · 630 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 79% to 90% on time.
- Tuesdays90% on time · p90 10 min · 563 flights
- Wednesdays90% on time · p90 10 min · 559 flights
- Saturdays88% on time · p90 15 min · 476 flights
- Mondays85% on time · p90 25 min · 643 flights
- Thursdays84% on time · p90 20 min · 642 flights
- Fridays83% on time · p90 25 min · 643 flights
- Sundays79% on time · p90 40 min · 608 flights
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