Historical on-time performance
Ontario to San Jose
333 miData through May 2026Source: US DOT · BTS
Flights on ONT–SJC arrive on time 86% of the time over the last 12 months.
On-time rate86%arrived within 15 min
p90 delay25 min1 in 10 flights is worse (tail risk)
Cancelled0.1%of scheduled flights
based on 1,319 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Southwest AirlinesOn-time86%Medianon timep9025 minCancel0.1%Flights1,319
Why flights run late
Delay causes
- Airline19%
- Weather0%
- Air traffic (NAS)2%
- Late aircraft79%
- Security0%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline100%
- Weather0%
- Air traffic (NAS)0%
- Security0%
Most cancellations here are attributed to Airline. Shares are among 1 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 ONT → SJC
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 — 97% on time.
- Mornings97% on time · p90 on time · 1,219 flights
- Middays92% on time · p90 10 min · 1,001 flights
- Afternoons80% on time · p90 30 min · 715 flights
- Evenings79% on time · p90 40 min · 829 flights
- Overnights71% on time · p90 60 min · 376 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 80% to 92% on time.
- Tuesdays92% on time · p90 5 min · 561 flights
- Wednesdays91% on time · p90 10 min · 560 flights
- Thursdays88% on time · p90 15 min · 644 flights
- Saturdays88% on time · p90 15 min · 482 flights
- Mondays86% on time · p90 20 min · 644 flights
- Fridays86% on time · p90 25 min · 646 flights
- Sundays80% on time · p90 30 min · 603 flights
Keep exploring