Flight Check

Best Airline: DEN to STL

Denver to St. Louis — airline reliability comparison

Frontier Airlines is the most reliable airline on the DEN to STL route with a 82% on-time rate, compared to SkyWest Airlines at 75%. Based on 1,284 flights tracked.

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

Source: Bureau of Transportation Statistics. Updated October 2026.

On-Time Rate by Airline

Frontier Airlines82%
United Airlines78%
Southwest Airlines76%
SkyWest Airlines75%

DEN to STL Airline Comparison

AirlineOn-Time %Cancel %Avg DelayFlights
Frontier AirlinesF9Best82%1.1%62m1,284
United AirlinesUA78%0.8%62m3,784
Southwest AirlinesWN76%0.8%55m8,030
SkyWest AirlinesOOWorst75%1.0%80m653

Route Overview

77%
Overall On-Time
59m
Avg Delay
0.9%
Cancel Rate
13,757
Total Flights
DEN to STL Route DetailsReturn: STL to DEN
DEN AirportSTL Airport

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