Route · SEA → DEN · 2020–2025 BTS data
Seattle to Denver
The SEA–DEN corridor (Seattle, WA → Denver, CO) runs ahead of the national average, served by 33 carriers across roughly 1,024 miles.
Data updated 2026-06-13
- 81.1%
- On-time
- +2.1 pts
- vs US avg
- 64 min
- Delay when late
- 37,112
- Flights
Cancelled
0.9%
Best Month
Nov 2024 89%
Worst Month
Jul 2025 63%
Distance
1,024 mi
Carriers
33
Monthly Performance
Recent 24 months of route data.
| Period | Flights | Delayed | Cancelled | Diverted | Carriers |
|---|---|---|---|---|---|
| Dec 2025 | 468 | 90 | 3 | 4 | DL,WN,F9,AS,UA |
| Nov 2025 | 466 | 63 | 12 | 0 | UA,DL,F9,AS,WN |
| Oct 2025 | 557 | 93 | 4 | 0 | AS,UA,WN,DL,F9 |
| Sep 2025 | 574 | 138 | 0 | 2 | UA,WN,DL,F9,AS |
| Aug 2025 | 644 | 215 | 5 | 9 | WN,F9,UA,AS,DL |
| Jul 2025 | 670 | 250 | 8 | 16 | AS,UA,WN,DL,F9 |
| Jun 2025 | 643 | 219 | 5 | 9 | AS,UA,WN,DL,F9 |
| May 2025 | 564 | 181 | 2 | 6 | AS,DL,OO,UA,WN,F9 |
| Apr 2025 | 482 | 122 | 1 | 1 | DL,F9,OO,UA,WN,AS |
| Mar 2025 | 473 | 75 | 0 | 1 | AS,OO,UA,WN,DL,F9 |
| Feb 2025 | 411 | 84 | 2 | 0 | AS,OO,UA,WN,DL,F9 |
| Jan 2025 | 447 | 56 | 1 | 1 | AS,OO,UA,WN,DL,F9 |
| Dec 2024 | 469 | 62 | 1 | 0 | AS,DL,F9,OO,UA,WN |
| Nov 2024 | 485 | 54 | 5 | 0 | OO,UA,WN,AS,DL,F9 |
| Oct 2024 | 568 | 82 | 1 | 0 | UA,AS,OO,WN,DL,F9 |
| Sep 2024 | 606 | 115 | 0 | 3 | WN,OO,UA,AS,DL,F9 |
| Aug 2024 | 671 | 203 | 2 | 7 | AS,DL,F9,WN,UA |
| Jul 2024 | 718 | 167 | 12 | 4 | AS,DL,F9,UA,WN |
| Jun 2024 | 683 | 187 | 3 | 2 | AS,DL,F9,UA,WN |
| May 2024 | 600 | 128 | 1 | 2 | AS,DL,F9,UA,WN |
| Apr 2024 | 504 | 98 | 3 | 1 | AS,DL,F9,OO,UA,WN |
| Mar 2024 | 494 | 103 | 8 | 0 | AS,DL,F9,UA,WN |
| Feb 2024 | 449 | 73 | 0 | 1 | AS,DL,F9,UA,WN |
| Jan 2024 | 482 | 89 | 35 | 0 | AS,DL,F9,WN,UA |
Cancellation Rate
0.9%
114 of 13,128 flights
Diversion Rate
0.5%
69 of 13,128 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 →DEN - Denver
Full on-time, delay-cause, and seasonal performance for Denver, CO.
Destination airport →Compare the two airports
See SEA and DEN 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–DEN.
Routes with a similar on-time rate
What the Data Says About SEA to DEN
37,112 tracked flights put the SEA to DEN pairing (Seattle to Denver) at a 81.1% on-time rate, squarely in line with the wider network. Delays that do occur run 63.9 minutes on average. Across the 1,024-mile route and its 33 carriers, the trailing 24 months show 0.9% cancelled and 0.5% diverted (13,128 flights sampled).
The monthly split is wide on this route: Nov 2024 posted the strongest performance at 89% on-time, while Jul 2025 came in at just 63% - a 26-point swing worth factoring into travel timing.
Frequently Asked Questions
How often are flights delayed from SEA to DEN? ▼
What is the cancellation rate for SEA to DEN? ▼
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Flight Guides
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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.