OnTimeStats

Historical on-time performance

San Francisco to Ontario

363 miData through Dec 2025Source: US DOT · BTS

Flights on SFO–ONT arrive on time 82% of the time over the last 12 months.

On-time rate82%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled0.7%of scheduled flights

based on 1,118 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Too close to call — no single carrier is clearly more on-time here.

  • SkyWest Airlines
    On-time84%
    Medianon time
    p9030 min
    Cancel2.0%
    Flights298
  • United Airlines
    On-time81%
    Medianon time
    p9035 min
    Cancel0.2%
    Flights820

Why flights run late

Delay causes

  • Airline30%
  • Weather2%
  • Air traffic (NAS)18%
  • Late aircraft50%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

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 (2023-01 .. 2025-12).

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 73% to 87% on time.

  • Mornings87% on time · p90 15 min · 969 flights
  • Evenings83% on time · p90 35 min · 321 flights
  • Middays78% on time · p90 35 min · 850 flights
  • Afternoons77% on time · p90 45 min · 1,046 flights
  • Overnights73% on time · p90 55 min · 1,070 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 76% to 82% on time.

  • Tuesdays82% on time · p90 30 min · 565 flights
  • Wednesdays82% on time · p90 35 min · 562 flights
  • Saturdays82% on time · p90 30 min · 531 flights
  • Thursdays78% on time · p90 40 min · 637 flights
  • Fridays77% on time · p90 45 min · 654 flights
  • Sundays77% on time · p90 50 min · 641 flights
  • Mondays76% on time · p90 50 min · 666 flights
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Methodology

A flight is on time when it arrives within 15 minutes of schedule — the US DOT / BTS standard. Median and p90(the “1-in-10 bad day”) are read from the full arrival-delay distribution, never averaged across periods.

Figures cover a carrier’s own BTS-coded flights. Cells below ~200 flights are flagged as limited data. All numbers are pre-computed from public BTS On-Time Performance data.