STL (St. Louis) to ORD (Chicago) flights arrive on time 75% of the time. The most reliable airline on this route is American Airlines at 83%. The average delay is 90 minutes. Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Source: Bureau of Transportation Statistics. Updated August 2026.STL → ORD
STL (St. Louis) to ORD (Chicago)
STL → ORD on-time performance by month
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JanFebMarAprMayJunJulAugSepOctNovDec
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This route is delayed fairly often. About 75% of flights arrive on schedule.
Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Accurate?
American Airlines is significantly more reliable on this route at 83% on time vs United Airlines at 66%.
Airline Comparison
American Airlines leads at 83% on time; United Airlines trails at 66%.
Accurate?
Good to know
Departing from STL
81% on timeTSA is currently ~5 min. Best time: 4 AM (about 5 min).
Arriving at ORD
75% on timeWhen flights into ORD are late, the average delay is 79 minutes. Build buffer if you have ground plans.
If connecting at ORD: TSA is ~5 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what American 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.