Historical on-time performance
Ontario to San Francisco
Flights on ONT–SFO arrive on time 72% of the time over the last 12 months.
based on 1,036 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- United AirlinesOn-time72%Medianon timep9050 minCancel0.4%Flights1,036
Why flights run late
Delay causes
- Airline18%
- Weather2%
- Air traffic (NAS)56%
- Late aircraft24%
- Security0%
Most delay minutes here are attributed to Air traffic (NAS).
When flights don't go
Why flights were cancelled
- Airline50%
- Weather0%
- Air traffic (NAS)50%
- Security0%
Most cancellations here are attributed to Airline. Shares are among 4 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 → SFO
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best time of day
On-time rates are fairly even by time of day on this route — ranging from 64% to 78% on time.
- Mornings78% on time · p90 40 min · 1,384 flights
- Afternoons76% on time · p90 55 min · 504 flights
- Middays71% on time · p90 50 min · 1,336 flights
- Overnights68% on time · p90 65 min · 271 flights
- Evenings64% on time · p90 75 min · 804 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 65% to 79% on time.
- Tuesdays79% on time · p90 35 min · 543 flights
- Saturdays79% on time · p90 40 min · 546 flights
- Wednesdays75% on time · p90 45 min · 555 flights
- Fridays71% on time · p90 55 min · 678 flights
- Thursdays71% on time · p90 55 min · 643 flights
- Sundays69% on time · p90 55 min · 663 flights
- Mondays65% on time · p90 75 min · 671 flights
Keep exploring