United Airlines SEA to DEN on-time performance
United Airlines nonstop flights from Seattle to Denver · Aug 2025 – Jul 2026
On-time arrivals
88%
arrived < 15 min late
Cancelled
0.7%
13 flights
Avg arrival delay
9 min
70 min when late
Rank on route
#1 of 6
route average 78% on time
Key facts
- United Airlines flights on SEA to DEN arrived on time 88% of the time in Aug 2025 – Jul 2026.
- 0.7% were cancelled, and 4% arrived an hour or more late.
- That ranks #1 of 6 airlines on this route, which averaged 78% on time overall.
- The largest source of delay minutes was late-arriving aircraft (42%).
On-time trend by month
Why this airline's flights were late
- Late-arriving aircraft42%
- Air traffic control & airport congestion31%
- Airline (crew, maintenance, cleaning, fueling)22%
- Extreme weather4%
- Security0%
Other airlines on SEA to DEN
- Alaska Airlines78% on time · 12 min avg delay
- Southwest Airlines68% on time · 17 min avg delay
- Delta Air Lines73% on time · 17 min avg delay
- Frontier Airlines77% on time · 15 min avg delay
- SkyWest Airlines85% on time · 10 min avg delay
Full SEA to DEN comparison →
United Airlines on-time record across all routes →
1,908 United Airlines flights tracked on this route; 13 cancelled, 8 diverted.
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. How we calculate this.