Delta Air Lines is the most reliable airline on the SEA to SAN route with a 84% on-time rate, compared to Southwest Airlines at 54%. Based on 6,188 flights tracked.
Source: Bureau of Transportation Statistics. Updated October 2026.Best Airline: SEA to SAN
Seattle to San Diego — airline reliability comparison
On-Time Rate by Airline
Delta Air Lines84%
Alaska Airlines78%
Southwest Airlines54%
SEA to SAN Airline Comparison
| Airline | On-Time % | Cancel % | Avg Delay | Flights |
|---|---|---|---|---|
| Delta Air LinesDLBest | 84% | 0.6% | 57m | 6,188 |
| Alaska AirlinesAS | 78% | 1.2% | 44m | 10,139 |
| Southwest AirlinesWNWorst | 54% | 0.0% | 44m | 149 |
Route Overview
80%
Overall On-Time
48m
Avg Delay
0.9%
Cancel Rate
16,592
Total Flights
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Data last updated October 2026. Source: Bureau of Transportation Statistics.