Route · SEA → ONT · 2020–2025 BTS data
Seattle to Ontario
The SEA–ONT corridor (Seattle, WA → Ontario, CA) runs ahead of the national average, served by 17 carriers across roughly 956 miles.
Data updated 2026-06-13
- 83.5%
- On-time
- +4.5 pts
- vs US avg
- 57 min
- Delay when late
- 12,866
- Flights
Cancelled
1.2%
Best Month
Sep 2025 91%
Worst Month
Dec 2025 73%
Distance
956 mi
Carriers
17
Monthly Performance
Recent 24 months of route data.
| Period | Flights | Delayed | Cancelled | Diverted | Carriers |
|---|---|---|---|---|---|
| Dec 2025 | 200 | 55 | 2 | 0 | F9,AS,OO |
| Nov 2025 | 211 | 35 | 7 | 0 | OO,F9,AS |
| Oct 2025 | 200 | 24 | 2 | 0 | AS,OO,F9 |
| Sep 2025 | 213 | 19 | 0 | 0 | OO,DL,F9,AS |
| Aug 2025 | 266 | 59 | 1 | 0 | OO,F9,AS,DL |
| Jul 2025 | 302 | 81 | 10 | 0 | AS,OO,F9 |
| Jun 2025 | 267 | 64 | 2 | 0 | AS,OO,F9 |
| May 2025 | 258 | 38 | 2 | 0 | AS,OO,F9 |
| Apr 2025 | 202 | 20 | 0 | 0 | F9,OO,AS |
| Mar 2025 | 183 | 29 | 0 | 0 | AS,OO,F9 |
| Feb 2025 | 147 | 38 | 6 | 0 | AS,OO,F9 |
| Jan 2025 | 167 | 25 | 1 | 8 | AS,OO,F9 |
| Dec 2024 | 175 | 24 | 1 | 1 | AS,F9,OO |
| Nov 2024 | 226 | 29 | 1 | 0 | OO,AS,F9 |
| Oct 2024 | 209 | 21 | 0 | 0 | AS,OO,F9 |
| Sep 2024 | 224 | 40 | 1 | 1 | OO,AS,F9 |
| Aug 2024 | 256 | 47 | 3 | 0 | AS,F9,OO |
| Jul 2024 | 276 | 48 | 4 | 0 | AS,F9,OO |
| Jun 2024 | 270 | 56 | 2 | 0 | AS,F9,OO |
| May 2024 | 254 | 43 | 0 | 0 | AS,F9,OO |
| Apr 2024 | 200 | 36 | 0 | 0 | AS,DL,OO |
| Mar 2024 | 152 | 29 | 0 | 0 | AS,DL |
| Feb 2024 | 133 | 21 | 0 | 1 | AS,DL |
| Jan 2024 | 143 | 23 | 15 | 0 | AS,DL |
Cancellation Rate
1.2%
60 of 5,134 flights
Diversion Rate
0.2%
11 of 5,134 flights
Explore origin & destination
On-time and delay data for the airports this route connects.
SEA - Seattle
Full on-time, delay-cause, and seasonal performance for Seattle, WA.
Origin airport →ONT - Ontario
Full on-time, delay-cause, and seasonal performance for Ontario, CA.
Destination airport →Compare the two airports
See SEA and ONT side by side on delays, cancellations, and reliability.
Open comparison tool →Similar routes
Other BTS-tracked routes with comparable performance or trip length to SEA–ONT.
Routes with a similar on-time rate
What the Data Says About SEA to ONT
Bureau of Transportation Statistics records show Seattle to Ontario (SEA to ONT) running a 83.5% on-time rate over 12,866 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 57.0 minutes. The 956-mile corridor is served by 17 carriers, and over the last 24 months 1.2% of 5,134 flights were cancelled, 0.2% diverted.
The monthly split is wide on this route: Sep 2025 posted the strongest performance at 91% on-time, while Dec 2025 came in at just 73% - a 19-point swing worth factoring into travel timing.
Frequently Asked Questions
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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.
Read our methodology - how this data is sourced, computed, and verified.
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.