Chicago (ORD) to St. Louis (STL): On-Time Performance
Data through May 2026
Chicago (ORD) to St. Louis (STL) effectively runs on two schedules. In October 2024, 90% of arrivals were on time; in December 2025 that fell to 59% — a 31-point seasonal swing. Across the full period the route averages 75% on-time against a national 78%. Morning departures also hold up better than evening ones (81% vs 62%), which matters most in the rough months.
- On-time
- 75%
- arrived <15 min late
- Avg delay
- 19 min
- completed flights
- Cancelled
- 1.8%
- Flights/day
- 8.4
- last 12 months
- Duration
- 1h 23m
- scheduled
- Distance
- 258 mi
Best airline from ORD to STL
5 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Republic Airwaysmost reliable | 83% | 12 min | 2.0% | 918 |
| Envoy Air | 79% | 12 min | 1.8% | 1,425 |
| United Airlines | 77% | 17 min | 0.7% | 1,009 |
| SkyWest Airlines | 70% | 24 min | 3.0% | 1,190 |
| American Airlines | 67% | 28 min | 1.6% | 1,183 |
Monthly on-time trend
Best time to fly from ORD to STL
Aim for departures around 1 p.m. (85% on-time); avoid 5 p.m. departures (52%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 75% | 19 min |
| Tuesdaybest | 79% | 16 min |
| Wednesday | 76% | 18 min |
| Thursday | 76% | 18 min |
| Friday | 72% | 21 min |
| Saturday | 78% | 13 min |
| Sunday | 69% | 25 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft42%
- Airline operations34%
- National airspace system14%
- Weather10%
Frequently asked questions
- How often are flights from ORD to STL delayed?
- 25% of ORD–STL flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 19 minutes.
- Which airline is most reliable from ORD to STL?
- Republic Airways has the best on-time record on this route at 83%, based on 918 flights. 5 airlines flew ORD–STL frequently enough to compare in this period.
- What is the best time of day to fly from ORD to STL?
- Departures around 1 p.m. have the best record (85% on-time), while departures around 5 p.m. have the worst (52%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from ORD to STL?
- The scheduled ORD–STL flight time averages 1h 23m over 258 miles. Actual arrival times vary — flights on this route land 15+ minutes late 25% of the time.
- How often are ORD to STL flights cancelled?
- 1.8% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, slightly above the national rate of 1.6%.
- What is the worst month to fly from ORD to STL?
- December 2025 was the roughest month in this dataset, with only 59% of arrivals on time. The best was October 2024 at 90%. If your dates are flexible, that 31-point gap is worth planning around.
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Based on 5,725 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.