PlainFlights

Route · ONT → SFO · 2020–2025 BTS data

Ontario to San Francisco

The ONT–SFO corridor (Ontario, CA → San Francisco, CA) runs ahead of the national average, served by 12 carriers across roughly 363 miles.

Data updated 2026-06-13

81.5%
On-time
+2.5 pts
vs US avg
75 min
Delay when late
8,435
Flights

Cancelled

1.2%

Best Month

Jan 2025 91%

Worst Month

May 2024 48%

Distance

363 mi

Carriers

12

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 104 25 2 0 F9,UA,OO
Nov 2025 105 25 2 0 UA,F9
Oct 2025 114 48 0 0 OO,UA,F9
Sep 2025 108 38 0 0 UA,OO,F9
Aug 2025 109 31 1 0 OO,F9,UA
Jul 2025 104 26 0 0 OO,UA,F9
Jun 2025 104 17 1 0 OO,UA,F9
May 2025 131 22 0 0 OO,UA,F9
Apr 2025 154 20 1 0 F9,OO,UA
Mar 2025 117 34 3 1 OO,UA,F9
Feb 2025 105 16 4 0 OO,UA,F9
Jan 2025 101 9 1 0 OO,UA,F9
Dec 2024 140 37 2 0 F9,OO,UA
Nov 2024 180 47 5 1 OO,UA,F9
Oct 2024 165 32 1 0 UA,OO,F9
Sep 2024 149 29 0 0 OO,UA,F9
Aug 2024 140 32 2 0 F9,OO,UA
Jul 2024 127 23 3 0 F9,OO,UA
Jun 2024 86 31 2 0 F9,OO,UA
May 2024 92 48 0 0 F9,OO,UA
Apr 2024 90 40 0 0 F9,OO,UA
Mar 2024 120 54 0 0 F9,OO,UA
Feb 2024 98 37 5 0 F9,OO
Jan 2024 98 26 0 0 F9,OO

Cancellation Rate

1.2%

35 of 2,841 flights

Diversion Rate

0.1%

2 of 2,841 flights

What the Data Says About ONT to SFO

8,435 tracked flights put the ONT to SFO pairing (Ontario to San Francisco) at a 81.5% on-time rate, squarely in line with the wider network. Delays that do occur run 75.4 minutes on average. Across the 363-mile route and its 12 carriers, the trailing 24 months show 1.2% cancelled and 0.1% diverted (2,841 flights sampled).

The monthly split is wide on this route: Jan 2025 posted the strongest performance at 91% on-time, while May 2024 came in at just 48% - a 43-point swing worth factoring into travel timing.

Frequently Asked Questions

How often are flights delayed from ONT to SFO?
Flights from Ontario to San Francisco have a 81.5% on-time rate based on 8,435 flights. The average delay is 75.4 minutes. The best recent month was Jan 2025 with 91% on-time.
What is the cancellation rate for ONT to SFO?
Over the last 24 months, 1.2% of flights on this route were cancelled (35 of 2,841 flights) and 0.1% were diverted.
How far is the flight from ONT to SFO?
The flight distance from Ontario (ONT) to San Francisco (SFO) is approximately 363 miles. This route is served by 12 carriers.
When is the best time to fly from ONT to SFO?
The best recent month for on-time performance was Jan 2025 (91% on-time). The worst was May 2024 (48% on-time). Consider booking during months with historically better performance.

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Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights Editorial

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.