Delta Air Lines is the most reliable airline on the SLC to SEA route with a 85% on-time rate, compared to Frontier Airlines at 70%. Based on 7,870 flights tracked.
Source: Bureau of Transportation Statistics. Updated October 2026.Best Airline: SLC to SEA
Salt Lake City to Seattle — airline reliability comparison
On-Time Rate by Airline
Delta Air Lines85%
SkyWest Airlines82%
Alaska Airlines77%
Frontier Airlines70%
SLC to SEA Airline Comparison
| Airline | On-Time % | Cancel % | Avg Delay | Flights |
|---|---|---|---|---|
| Delta Air LinesDLBest | 85% | 0.5% | 54m | 7,870 |
| SkyWest AirlinesOO | 82% | 0.0% | 57m | 1,629 |
| Alaska AirlinesAS | 77% | 1.4% | 48m | 4,434 |
| Frontier AirlinesF9Worst | 70% | 2.5% | 75m | 121 |
Route Overview
82%
Overall On-Time
53m
Avg Delay
0.7%
Cancel Rate
14,131
Total Flights
Flying out of SLC? We'll brief you.
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Data last updated October 2026. Source: Bureau of Transportation Statistics.