Historical on-time performance
San Francisco to Ontario
363 miData through May 2026Source: US DOT · BTS
Flights on SFO–ONT arrive on time 81% of the time over the last 12 months.
On-time rate81%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled0.3%of scheduled flights
based on 1,037 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- United AirlinesOn-time81%Medianon timep9035 minCancel0.3%Flights1,037
Why flights run late
Delay causes
- Airline31%
- Weather0%
- Air traffic (NAS)19%
- Late aircraft51%
- Security0%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline33%
- Weather0%
- Air traffic (NAS)67%
- Security0%
Most cancellations here are attributed to Air traffic (NAS). Shares are among 3 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 SFO → 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 — 88% on time.
- Mornings88% on time · p90 15 min · 948 flights
- Evenings82% on time · p90 40 min · 326 flights
- Afternoons79% on time · p90 45 min · 1,052 flights
- Middays78% on time · p90 35 min · 908 flights
- Overnights75% on time · p90 55 min · 1,065 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 77% to 85% on time.
- Wednesdays85% on time · p90 30 min · 555 flights
- Tuesdays83% on time · p90 25 min · 543 flights
- Saturdays82% on time · p90 30 min · 548 flights
- Sundays79% on time · p90 40 min · 655 flights
- Thursdays78% on time · p90 35 min · 638 flights
- Fridays78% on time · p90 45 min · 678 flights
- Mondays77% on time · p90 50 min · 682 flights
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