BTS DATA COMPLETE THROUGH JUNE 2026HISTORICAL ODDS · NOT LIVE FLIGHT STATUS
DelayOddsKnow the route before you book
MDW→STL

Chicago, IL (MDW) to St. Louis, MO (STL) flight delay odds

80.6% of 1,705 official scheduled MDW-to-STL flights arrived on time; 11.5% arrived at least 30 minutes late and 1.1% were cancelled during July 2025–June 2026.

Source: U.S. Bureau of Transportation Statistics · Reporting window: July 2025–June 2026 · Updated September 16, 2026

HISTORICAL ROUTE SIGNALLower disruption
80.6%arrived on time
11.5%30+ min late
1.1%cancelled
1,705scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late5.6%all scheduled flights
120+ minutes late2.2%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival+2.5 mincompleted flights

Which departure time was most reliable for MDW to STL?

Among qualifying MDW-to-STL departure window results, Early morning had the highest on-time rate: 93.7% of 412 flights. Night was lowest at 63.9% across 169 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning41293.7%3.6%0.2%
Late morning36087.8%5.3%1.7%
Afternoon38278.8%13.4%1.0%
Evening38269.1%18.1%1.3%
Night16963.9%24.9%1.2%

Which weekday was most reliable for MDW to STL?

Among qualifying MDW-to-STL weekday results, Tuesday had the highest on-time rate: 86.2% of 269 flights. Sunday was lowest at 74.9% across 235 flights.

DayFlightsOn time30+ minCancelled
Monday26276.0%17.2%0.8%
Tuesday26986.2%7.4%0.4%
Wednesday26085.0%6.5%1.5%
Thursday25679.7%9.8%0.4%
Friday25781.7%10.9%1.2%
Saturday16680.1%12.0%2.4%
Sunday23574.9%17.4%1.3%

Which airline was most reliable for MDW to STL?

Only Southwest Airlines met the MDW-to-STL airline threshold: 80.6% of 1,705 scheduled flights arrived on time during July 2025–June 2026.

AirlineFlightsOn time30+ minCancelled
Southwest Airlines1,70580.6%11.5%1.1%

Which month was most reliable for MDW to STL?

Among qualifying MDW-to-STL month results, September 2025 had the highest on-time rate: 92.7% of 151 flights. July 2025 was lowest at 70.4% across 169 flights.

MonthFlightsOn time30+ minCancelled
July 202516970.4%17.2%1.2%
August 202515483.8%9.7%0.6%
September 202515192.7%2.6%0.0%
October 202513086.9%8.5%0.0%
November 202512782.7%7.1%3.1%
December 202513977.7%15.8%0.7%
January 202612084.2%11.7%0.0%
February 202611088.2%7.3%0.0%
March 202613672.1%16.9%2.9%
April 202615184.1%10.6%1.3%
May 202615678.2%10.9%0.6%
June 202616271.6%17.3%1.9%

What drove MDW to STL delay minutes?

Late aircraft was the largest recorded MDW-to-STL delay category, accounting for 53.8% of 18,791 BTS-attributed delay minutes during July 2025–June 2026.

Airline33.3%
Late aircraft53.8%
National airspace10.7%
Weather2.1%
Security0.0%
This is historical evidence, not a forecast.

Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.