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Route · MDW → STL · 2020–2025 BTS data

Chicago to St. Louis

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), MDW to STL (Chicago to St. Louis) ranks #1070 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

82.5%
On-time
+3.5 pts
vs US avg
59 min
Delay when late
10,760
Flights
#1070 of 4927
Corpus placement

Cancelled

1.2%

Best Month

Oct 2024 94%

Worst Month

May 2024 71%

Distance

251 mi

Carriers

1

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 139 30 1 0 WN
Nov 2025 127 18 4 0 WN
Oct 2025 130 17 0 0 WN
Sep 2025 151 11 0 0 WN
Aug 2025 154 24 1 0 WN
Jul 2025 169 48 2 0 WN
Jun 2025 162 33 1 0 WN
May 2025 169 26 2 0 WN
Apr 2025 160 19 1 1 WN
Mar 2025 131 17 0 0 WN
Feb 2025 111 11 2 0 WN
Jan 2025 127 19 6 0 WN
Dec 2024 151 25 1 0 WN
Nov 2024 142 9 0 0 WN
Oct 2024 157 9 1 0 WN
Sep 2024 162 18 0 0 WN
Aug 2024 170 23 1 0 WN
Jul 2024 183 47 3 1 WN
Jun 2024 174 37 0 0 WN
May 2024 155 45 0 0 WN
Apr 2024 158 28 1 0 WN
Mar 2024 163 20 0 0 WN
Feb 2024 129 12 0 0 WN
Jan 2024 146 27 15 0 WN

MDW–STL seasonal on-time pattern

Best: February (88.8%) · weakest: June (73.4%)

70%75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 83.3%

Strongest calendar month

February

88.8% on-time · ~125 flights/mo

Busiest calendar month

July

~181 flights/mo avg

Weakest calendar month

June

73.4% on-time · ~160 flights/mo

Cancellation Rate

1.2%

42 of 3,620 flights

Diversion Rate

0.1%

2 of 3,620 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

MDW - Chicago

Full on-time, delay-cause, and seasonal performance for Chicago, IL.

MDW on-time profile

STL - St. Louis

Full on-time, delay-cause, and seasonal performance for St. Louis, MO.

STL on-time profile

Compare the two airports

See MDW and STL side by side on delays, cancellations, and reliability.

Compare MDW vs STL

Origin-hub reliability standing

Mid-pack among MDW departures

From MDW, this corridor sits with 51 other 75–85% on-time routes out of 69 tracked departures, not the hub's reliability leaders (0 at ≥85%) and not the softest ( 18 below 75%). Destination: St. Louis · fleet on-time rank #2152 of 4927.

What the Data Says About MDW to STL

Bureau of Transportation Statistics records show Chicago to St. Louis (MDW to STL) running a 82.5% on-time rate over 10,760 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 58.7 minutes. The 251-mile corridor is served by 1 carrier, and over the last 24 months 1.2% of 3,620 flights were cancelled, 0.1% diverted.

The monthly split is wide on this route: Oct 2024 posted the strongest performance at 94% on-time, while May 2024 came in at just 71% - a 23-point swing worth factoring into travel timing.

On the multi-year calendar, MDW–STL peaks in February at 88.8% on-time while July carries the heaviest traffic (~181 flights per month) ; the softest month is June at 73.4%, a 15.4-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does MDW to STL rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, MDW to STL ranks #1070 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from MDW to STL? ▼
Flights from Chicago to St. Louis have a 82.5% on-time rate based on 10,760 flights. The average delay is 58.7 minutes. The best recent month was Oct 2024 with 94% on-time.
What is the cancellation rate for MDW to STL? ▼
Over the last 24 months, 1.2% of flights on this route were cancelled (42 of 3,620 flights) and 0.1% were diverted.
How far is the flight from MDW to STL? ▼
The flight distance from Chicago (MDW) to St. Louis (STL) is approximately 251 miles. This route is served by 1 carrier.
When is the best time to fly from MDW to STL? ▼
The best recent month for on-time performance was Oct 2024 (94% on-time). The worst was May 2024 (71% on-time). Consider booking during months with historically better performance.

Airports on this route

MDW Airport

Chicago
STL Airport

St. Louis
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using MDW–STL data

MDW–STL runs 3.5 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare MDW and STL airport profiles: delay causes and top routes differ even on the same corridor. MDW airport
  • If your dates flex, February (88.8% on-time) beats June (73.4%) on this corridor. Seasonal chart
  • 4 other routes post a similar 82.5% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.