DEN to SEA flight delays & on-time performance
Nonstop flights from Denver International Airport to Seattle–Tacoma International Airport · 1,024 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at DEN or SEA right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Denver (DEN) to Seattle (SEA) arrived on time 75% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 0.6% were cancelled, and 7% arrived an hour or more late.
- United Airlines was the most punctual airline here (81% on time); Southwest Airlines was the least (61%).
- Departures scheduled around 7am did best (89% on time); around 9pm did worst (59%).
- Saturday was the most reliable day to fly (78% on time) and Thursday the least (71%).
- The largest source of delay minutes was late-arriving aircraft (43%).
Which airline is most on time from DEN to SEA?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| United Airlines | 81% | 0.5% | 12 min | 5.7% | 1,906 |
| Frontier Airlines | 80% | 1.4% | 12 min | 5.9% | 431 |
| Delta Air Lines | 79% | 0.9% | 19 min | 7.0% | 868 |
| SkyWest AirlinesRegional airline operating flights for United Express, Delta Connection, American Eagle and Alaska. | 76% | 0.5% | 18 min | 9.1% | 220 |
| Alaska Airlines | 75% | 0.8% | 15 min | 6.6% | 1,551 |
| Southwest Airlines | 61% | 0.2% | 20 min | 8.8% | 1,341 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am89%614 flights
- 7am89%507 flights
- 8am83%639 flights
- 9am79%181 flights
- 10am71%108 flights
- 11am84%443 flights
- 12pm75%528 flights
- 1pm82%398 flights
- 2pm76%87 flights
- 3pm73%390 flights
- 4pm69%362 flights
- 5pm61%180 flights
- 6pm60%356 flights
- 7pm65%771 flights
- 8pm62%285 flights
- 9pm59%360 flights
- 10pm55%97 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday75%0.5% cancelled
- Tuesday77%0.4% cancelled
- Wednesday77%0.3% cancelled
- Thursday71%0.5% cancelled
- Friday72%1.2% cancelled
- Saturday78%0.8% cancelled
- Sunday73%0.5% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft43%
- Airline (crew, maintenance, cleaning, fueling)37%
- Air traffic control & airport congestion18%
- Extreme weather2%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)55%
- Extreme weather28%
- Air traffic control & airport congestion18%
- Security0%
DEN to SEA: common questions
- How often are DEN to SEA flights on time?
- 75% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Denver to Seattle cancelled?
- 0.6% of scheduled flights were cancelled (40 of 6,317).
- How long are typical delays?
- Across all flights the average arrival delay was 16 min (early arrivals count as zero). Flights that were late arrived 57 min behind schedule on average, and 6.9% of flights were an hour or more late.
- How long is taxi time at DEN?
- Flights on this route spent 19 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SEA to DEN — 78% on time
More flights from Denver
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: DEN → SEA, nonstop flights by US airlines that report to the DOT. How we calculate this.