Miami (MIA) to St. Louis (STL): On-Time Performance
Data through May 2026
Miami (MIA) to St. Louis (STL) effectively runs on two schedules. In October 2024, 91% of arrivals were on time; in August 2025 that fell to 53% — a 38-point seasonal swing. Across the full period the route averages 73% on-time against a national 78%. Morning departures also hold up better than evening ones (92% vs 65%), which matters most in the rough months.
- On-time
- 73%
- arrived <15 min late
- Avg delay
- 19 min
- completed flights
- Cancelled
- 0.8%
- Flights/day
- 3.1
- last 12 months
- Duration
- 3h 1m
- scheduled
- Distance
- 1,068 mi
Best airline from MIA to STL
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Envoy Airmost reliable | 87% | 7 min | 0.4% | 239 |
| American Airlines | 71% | 21 min | 1.1% | 1,005 |
| Southwest Airlines | 71% | 20 min | 0.7% | 871 |
Monthly on-time trend
Best time to fly from MIA to STL
Aim for departures around 5 a.m. (100% on-time); avoid 7 p.m. departures (32%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 74% | 23 min |
| Tuesdaybest | 78% | 18 min |
| Wednesday | 78% | 13 min |
| Thursday | 73% | 20 min |
| Friday | 73% | 17 min |
| Saturday | 73% | 18 min |
| Sunday | 64% | 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 aircraft52%
- Airline operations29%
- National airspace system14%
- Weather5%
Frequently asked questions
- How often are flights from MIA to STL delayed?
- 27% of MIA–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 MIA to STL?
- Envoy Air has the best on-time record on this route at 87%, based on 239 flights. 3 airlines flew MIA–STL frequently enough to compare in this period.
- What is the best time of day to fly from MIA to STL?
- Departures around 5 a.m. have the best record (100% on-time), while departures around 7 p.m. have the worst (32%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from MIA to STL?
- The scheduled MIA–STL flight time averages 3h 1m over 1,068 miles. Actual arrival times vary — flights on this route land 15+ minutes late 27% of the time.
- How often are MIA to STL flights cancelled?
- 0.8% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from MIA to STL?
- August 2025 was the roughest month in this dataset, with only 53% of arrivals on time. The best was October 2024 at 91%. If your dates are flexible, that 38-point gap is worth planning around.
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Based on 2,119 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.