Flight Check

Best Airline: PHL to SEA

Philadelphia to Seattle — airline reliability comparison

Alaska Airlines is the most reliable airline on the PHL to SEA route with a 74% on-time rate, compared to Delta Air Lines at 72%. Based on 2,240 flights tracked.

This route involves weather-prone airports, which can affect reliability regardless of airline.

Source: Bureau of Transportation Statistics. Updated October 2026.

On-Time Rate by Airline

Alaska Airlines74%
American Airlines73%
Delta Air Lines72%

PHL to SEA Airline Comparison

AirlineOn-Time %Cancel %Avg DelayFlights
Alaska AirlinesASBest74%2.0%54m2,240
American AirlinesAA73%1.6%59m1,763
Delta Air LinesDLWorst72%0.0%76m82

Route Overview

73%
Overall On-Time
59m
Avg Delay
1.6%
Cancel Rate
4,091
Total Flights
PHL to SEA Route DetailsReturn: SEA to PHL
PHL AirportSEA Airport

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Data last updated October 2026. Source: Bureau of Transportation Statistics.