MDW to STL flight delays & on-time performance
Nonstop flights from Chicago Midway International Airport to St. Louis Lambert International Airport · 251 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at MDW or STL right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Chicago (MDW) to St. Louis (STL) arrived on time 82% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 1.3% were cancelled, and 5% arrived an hour or more late.
- Southwest Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 6am did best (98% on time); around 6pm did worst (64%).
- Wednesday was the most reliable day to fly (89% on time) and Sunday the least (76%).
- The largest source of delay minutes was late-arriving aircraft (53%).
Which airline is most on time from MDW to STL?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Southwest Airlines | 82% | 1.3% | 12 min | 5.5% | 1,708 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am98%149 flights
- 7am88%147 flights
- 8am95%83 flights
- 9am96%129 flights
- 10am89%88 flights
- 11am84%152 flights
- 12pm82%40 flights
- 1pm89%143 flights
- 2pm72%135 flights
- 3pm79%19 flights
- 4pm75%64 flights
- 5pm68%118 flights
- 6pm64%94 flights
- 7pm82%84 flights
- 8pm79%74 flights
- 9pm66%147 flights
- 10pm60%31 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday76%1.9% cancelled
- Tuesday86%0.4% cancelled
- Wednesday89%1.2% cancelled
- Thursday81%0.8% cancelled
- Friday81%1.5% cancelled
- Saturday84%2.4% cancelled
- Sunday76%1.3% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft53%
- Airline (crew, maintenance, cleaning, fueling)34%
- Air traffic control & airport congestion10%
- Extreme weather2%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather68%
- Airline (crew, maintenance, cleaning, fueling)27%
- Air traffic control & airport congestion5%
- Security0%
MDW to STL: common questions
- How often are MDW to STL flights on time?
- 82% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Chicago to St. Louis cancelled?
- 1.3% of scheduled flights were cancelled (22 of 1,708).
- How long are typical delays?
- Across all flights the average arrival delay was 12 min (early arrivals count as zero). Flights that were late arrived 60 min behind schedule on average, and 5.5% of flights were an hour or more late.
- How long is taxi time at MDW?
- Flights on this route spent 14 min taxiing from the gate to takeoff on average.
Related routes
Return trip: STL to MDW — 80% on time
More flights from Chicago
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: MDW → STL, nonstop flights by US airlines that report to the DOT. How we calculate this.