Alaska Airlines is the most reliable airline on the DCA to SEA route with a 82% on-time rate, compared to Delta Air Lines at 72%. Based on 2,612 flights tracked.
Source: Bureau of Transportation Statistics. Updated October 2026.Best Airline: DCA to SEA
Washington to Seattle — airline reliability comparison
On-Time Rate by Airline
Alaska Airlines82%
Delta Air Lines72%
DCA to SEA Airline Comparison
| Airline | On-Time % | Cancel % | Avg Delay | Flights |
|---|---|---|---|---|
| Alaska AirlinesASBest | 82% | 0.8% | 62m | 2,612 |
| Delta Air LinesDLWorst | 72% | 2.6% | 113m | 509 |
Route Overview
81%
Overall On-Time
74m
Avg Delay
1.1%
Cancel Rate
3,121
Total Flights
Flying out of DCA? We'll brief you.
Delays, TSA, weather, gates — we'll let you know if something matters.
Data last updated October 2026. Source: Bureau of Transportation Statistics.