Route · ONT → SFO · 2020–2025 BTS data
Ontario to San Francisco
According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), ONT to SFO (Ontario to San Francisco) ranks #1444 of 4927 tracked domestic routes by total flights (most flights = #1).
Data updated 2026-06-13
- 81.5%
- On-time
- +2.5 pts
- vs US avg
- 75 min
- Delay when late
- 8,435
- Flights
- #1444 of 4927
- Corpus placement
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 |
ONT–SFO seasonal on-time pattern
Best: April (85.7%) · weakest: December (78.1%)
Strongest calendar month
April
85.7% on-time · ~111 flights/mo
Busiest calendar month
October
~136 flights/mo avg
Weakest calendar month
December
78.1% on-time · ~112 flights/mo
Cancellation Rate
1.2%
35 of 2,841 flights
Diversion Rate
0.1%
2 of 2,841 flights
Explore origin & destination
On-time and delay data for the airports this route connects.
ONT - Ontario
Full on-time, delay-cause, and seasonal performance for Ontario, CA.
ONT on-time profileSFO - San Francisco
Full on-time, delay-cause, and seasonal performance for San Francisco, CA.
SFO on-time profileCompare the two airports
See ONT and SFO side by side on delays, cancellations, and reliability.
Compare ONT vs SFOOrigin-hub reliability standing
Mid-pack among ONT departures
From ONT, this corridor sits with 9 other 75–85% on-time routes out of 21 tracked departures, not the hub's reliability leaders (10 at ≥85%) and not the softest ( 2 below 75%). Destination: San Francisco · fleet on-time rank #2552 of 4927.
Similar routes
Other BTS-tracked routes with comparable performance or trip length to ONT–SFO.
Routes with a similar on-time rate
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.
On the multi-year calendar, ONT–SFO peaks in April at 85.7% on-time while October carries the heaviest traffic (~136 flights per month) ; the softest month is December at 78.1%, a 7.6-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.
Frequently Asked Questions
Where does ONT to SFO rank among US routes by traffic? ▼
How often are flights delayed from ONT to SFO? ▼
What is the cancellation rate for ONT to SFO? ▼
How far is the flight from ONT to SFO? ▼
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Airports on this route
Data source
Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.
Read our methodology - how this data is sourced, computed, and verified.
Using ONT–SFO data
ONT–SFO is mid-pack at 81.5% on-time; month and carrier mix move more than the corridor headline.
- Compare ONT and SFO airport profiles: delay causes and top routes differ even on the same corridor. ONT airport
- If your dates flex, April (85.7% on-time) beats December (78.1%) on this corridor. Seasonal chart
- 4 other routes post a similar 81.5% on-time rate; compare before you commit to this pairing. Similar routes
On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.
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.