Flight Check

Best Airline: STL to PHL

St. Louis to Philadelphia — airline reliability comparison

Republic Airways is the most reliable airline on the STL to PHL route with a 90% on-time rate, compared to Frontier Airlines at 58%. Based on 323 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

Republic Airways90%
PSA Airlines85%
American Airlines84%
Southwest Airlines81%
Frontier Airlines58%

STL to PHL Airline Comparison

AirlineOn-Time %Cancel %Avg DelayFlights
Republic AirwaysYXBest90%1.8%59m323
PSA AirlinesOH85%4.4%100m393
American AirlinesAA84%1.6%160m1,954
Southwest AirlinesWN81%0.7%51m2,421
Frontier AirlinesF9Worst58%17.1%127m29

Route Overview

81%
Overall On-Time
93m
Avg Delay
1.7%
Cancel Rate
5,211
Total Flights
STL to PHL Route DetailsReturn: PHL to STL
STL AirportPHL Airport

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