Denver to Seattle — airline reliability comparison
SkyWest Airlines is the most reliable airline on the DEN to SEA route with a 82% on-time rate, compared to Southwest Airlines at 67%. Based on 478 flights tracked.
This route involves weather-prone airports and high-congestion airports, which can affect reliability regardless of airline.
Source: Bureau of Transportation Statistics. Updated October 2026.| Airline | On-Time % | Cancel % | Avg Delay | Flights |
|---|---|---|---|---|
| SkyWest AirlinesOOBest | 82% | 0.3% | 71m | 478 |
| Delta Air LinesDL | 82% | 0.8% | 84m | 3,412 |
| United AirlinesUA | 80% | 0.7% | 58m | 7,007 |
| Alaska AirlinesAS | 76% | 1.0% | 57m | 5,640 |
| Frontier AirlinesF9 | 72% | 0.9% | 56m | 1,592 |
| Southwest AirlinesWNWorst | 67% | 0.5% | 47m | 5,244 |
Delays, TSA, weather, gates — we'll let you know if something matters.
Data last updated October 2026. Source: Bureau of Transportation Statistics.