Route · SEA → DEN · 2020–2025 BTS data
Seattle to Denver
According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to DEN (Seattle to Denver) ranks #50 of 4927 tracked domestic routes by total flights (most flights = #1).
Data updated 2026-06-13
- 81.1%
- On-time
- +2.1 pts
- vs US avg
- 64 min
- Delay when late
- 37,112
- Flights
- #50 of 4927
- Corpus placement
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 |
SEA–DEN seasonal on-time pattern
Best: November (87.1%) · weakest: June (73.8%)
Strongest calendar month
November
87.1% on-time · ~487 flights/mo
Busiest calendar month
August
~616 flights/mo avg
Weakest calendar month
June
73.8% on-time · ~569 flights/mo
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.
SEA on-time profileDEN - Denver
Full on-time, delay-cause, and seasonal performance for Denver, CO.
DEN on-time profileCompare the two airports
See SEA and DEN side by side on delays, cancellations, and reliability.
Compare SEA vs DENOrigin-hub reliability standing
Mid-pack among SEA departures
From SEA, this corridor sits with 63 other 75–85% on-time routes out of 89 tracked departures, not the hub's reliability leaders (25 at ≥85%) and not the softest ( 1 below 75%). Destination: Denver · fleet on-time rank #2723 of 4927.
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.
On the multi-year calendar, SEA–DEN peaks in November at 87.1% on-time while August carries the heaviest traffic (~616 flights per month) ; the softest month is June at 73.8%, a 13.3-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.
Frequently Asked Questions
Where does SEA to DEN rank among US routes by traffic? ▼
How often are flights delayed from SEA to DEN? ▼
What is the cancellation rate for SEA to DEN? ▼
How far is the flight from SEA to DEN? ▼
When is the best time to fly from SEA to DEN? ▼
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 SEA–DEN data
SEA–DEN is mid-pack at 81.1% on-time; month and carrier mix move more than the corridor headline.
- Compare SEA and DEN airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
- If your dates flex, November (87.1% on-time) beats June (73.8%) on this corridor. Seasonal chart
- 4 other routes post a similar 81.1% 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.