Historical on-time performance
Ontario to Oakland
362 miData through May 2026Source: US DOT · BTS
Flights on ONT–OAK arrive on time 86% of the time over the last 12 months.
On-time rate86%arrived within 15 min
p90 delay20 min1 in 10 flights is worse (tail risk)
Cancelled0.4%of scheduled flights
based on 1,514 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 timep9020 minCancel0.4%Flights1,514
Why flights run late
Delay causes
- Airline31%
- Weather0%
- Air traffic (NAS)4%
- Late aircraft65%
- Security0%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline17%
- Weather33%
- Air traffic (NAS)50%
- Security0%
Most cancellations here are attributed to Air traffic (NAS). 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 ONT → OAK
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 · 1,395 flights
- Middays90% on time · p90 10 min · 1,027 flights
- Afternoons80% on time · p90 30 min · 842 flights
- Evenings80% on time · p90 30 min · 854 flights
- Overnights77% on time · p90 50 min · 580 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 81% to 91% on time.
- Saturdays91% on time · p90 10 min · 493 flights
- Tuesdays90% on time · p90 10 min · 649 flights
- Wednesdays89% on time · p90 15 min · 649 flights
- Mondays88% on time · p90 15 min · 728 flights
- Thursdays86% on time · p90 20 min · 731 flights
- Fridays83% on time · p90 25 min · 740 flights
- Sundays81% on time · p90 35 min · 708 flights
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