Delta Air Lines is the most reliable airline on the SEA to MIA route with a 80% on-time rate, compared to Alaska Airlines at 77%. Based on 590 flights tracked.
Source: Bureau of Transportation Statistics. Updated October 2026.Best Airline: SEA to MIA
Seattle to Miami — airline reliability comparison
On-Time Rate by Airline
Delta Air Lines80%
American Airlines79%
Alaska Airlines77%
SEA to MIA Airline Comparison
| Airline | On-Time % | Cancel % | Avg Delay | Flights |
|---|---|---|---|---|
| Delta Air LinesDLBest | 80% | 1.0% | 54m | 590 |
| American AirlinesAA | 79% | 0.6% | 80m | 1,439 |
| Alaska AirlinesASWorst | 77% | 1.3% | 49m | 1,364 |
Route Overview
78%
Overall On-Time
64m
Avg Delay
0.9%
Cancel Rate
3,393
Total Flights
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Data last updated October 2026. Source: Bureau of Transportation Statistics.