ORD to STL flight delays

ORD STL Chicago O'Hare to St. Louis Lambert · 258 miles

8,052 flights were scheduled from ORD to STL over July 2023 through June 2026. Of the 7,894 that made the trip, 76% reached the gate less than 15 minutes behind schedule. These are arrival figures: “on time” means the flight reached the gate less than 15 minutes behind schedule. Arrivals are what decide whether you make the connection, so route and airline pages are scored on them rather than on pushback.

Data through June 2026 · Bureau of Transportation Statistics

The route in brief

Flights in the window
8,052
Arrived on time
76%
Cancelled
1.8%
Scheduled distance
258 miles

Cancellations are counted against everything scheduled. Diverted flights are counted with them rather than as very late arrivals, which is why the on-time share and the cancellation rate do not add up to everything that happened.

Airline by airline

Airlines with at least 100 flights on ORD–STL, busiest first. Same route, same weather, same air traffic — which makes this the fairest comparison on the site.

Airline Arrived on time Typical delay Cancelled Flights
Envoy Air 79.6% 50 min 1.8% 2,166
American Airlines 66.6% 88 min 1.6% 1,637
United Airlines 79.2% 70 min 0.8% 1,601
SkyWest Airlines 70.9% 72 min 2.7% 1,420
Republic Airways 83.5% 71 min 2% 1,228

Month by month

July was the month to avoid on ORD–STL: 67.3% of flights arrived on time, against 82.4% in September. Each bar pools three years of that calendar month.

Share of flights that arrived on time, by calendar month. Best month in green, worst in amber. The hairline sits at the overall rate, 76%.
Arrival on-time share, ORD to STL, by calendar month
Month Share flights that arrived on time Flights
January 72.1% 478
February 79.2% 514
March 74.6% 703
April 77.7% 816
May 77.1% 854
June 72.3% 831
July 67.3% 724
August 73.8% 718
September 82.4% 630
October 80.9% 656
November 80.6% 582
December 74.8% 546

Both ends of the route

A route’s record is built out of two airports’ habits. The hour-by-hour grid for each is on its own page.

ORD to STL in one number

ORD → STL

When a flight on this route was late, it was late by about 71 min.

July 2023–June 2026 · 8,052 flights

76% of flights arrived on time

Questions about ORD to STL

Which airline is most reliable from ORD to STL?
Republic Airways — its flights on this pairing arrived on time 83.5% of the time, with 1,228 scheduled. American Airlines came in at 66.6% over 1,637 scheduled. Airlines with fewer than 100 flights on the route are not rated.
What is the worst month to fly ORD to STL?
July, at 67.3% of arrivals on time, with 724 flights scheduled. September was the best of the year at 82.4%.
How late are ORD–STL flights when they are late?
71 min on average, counting only the flights that arrived 15 minutes or more behind schedule. The on-time flights are left out of that average on purpose — mixing them in would flatter it.
How often is the ORD to STL flight cancelled?
1.8% of scheduled flights on this route were cancelled, July 2023 through June 2026. Diverted flights are counted with the cancellations rather than as late arrivals.
Are these departure or arrival numbers?
Arrival. A flight counts as on time here if it reached the gate at STL less than 15 minutes behind schedule. Airport pages score departures instead, because that is the number you can act on when you pick a booking time.