STL (St. Louis) to DEN (Denver) flights arrive on time 78% of the time. The most reliable airline on this route is SkyWest Airlines at 90%. The average delay is 68 minutes. Delays on this route are most often caused by the incoming plane arriving late.
Source: Bureau of Transportation Statistics. Updated August 2026.STL → DEN
STL (St. Louis) to DEN (Denver)
STL → DEN on-time performance by month
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JanFebMarAprMayJunJulAugSepOctNovDec
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This route is on time most of the time. About 78% of flights arrive on schedule.
Delays on this route are most often caused by the incoming plane arriving late.
Accurate?
SkyWest Airlines is significantly more reliable on this route at 90% on time vs Frontier Airlines at 72%.
Airline Comparison
SkyWest Airlines leads at 90% on time; Frontier Airlines trails at 72%.
Accurate?
Good to know
Departing from STL
81% on timeTSA is currently ~5 min. Best time: 4 AM (about 5 min).
Arriving at DEN
79% on timeWhen flights into DEN are late, the average delay is 69 minutes. Build buffer if you have ground plans.
If connecting at DEN: TSA is ~5 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what SkyWest Airlines owes you — refund rights, action plan, complaint email. Free.
Flying out of STL? We'll brief you.
Delays, TSA, weather, gates — we'll let you know if something matters.
Know someone flying soon?
Send them the link — delay data, TSA waits, weather, all free.
Data last updated August 2026. Source: Bureau of Transportation Statistics.