St. Louis (STL) to Miami (MIA): On-Time Performance
Data through July 2026
The calendar drives reliability on STL–MIA. April 2026 flights landed on schedule 94% of the time, but December 2024 dropped to 71% — a gap of 23 points. Across the full period the route averages 82% on-time against a national 78%. Morning departures also hold up better than evening ones (87% vs 73%), which matters most in the rough months.
- On-time
- 82%
- arrived <15 min late
- Avg delay
- 12 min
- completed flights
- Cancelled
- 0.9%
- Flights/day
- 3.2
- last 12 months
- Duration
- 2h 47m
- scheduled
- Distance
- 1,068 mi
Best airline from STL to MIA
3 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| American Airlinesmost reliable | 88% | 11 min | 1.0% | 1,060 |
| Envoy Air | 80% | 13 min | 0.7% | 276 |
| Southwest Airlines | 76% | 13 min | 0.8% | 912 |
Monthly on-time trend
Best time to fly from STL to MIA
Aim for departures around 5 a.m. (91% on-time); avoid 5 p.m. departures (65%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 84% | 13 min |
| Tuesday | 85% | 15 min |
| Wednesdaybest | 89% | 6 min |
| Thursday | 87% | 8 min |
| Friday | 84% | 10 min |
| Saturday | 74% | 15 min |
| Sunday | 75% | 16 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft36%
- Airline operations35%
- National airspace system22%
- Weather7%
Frequently asked questions
- How often are flights from STL to MIA delayed?
- 18% of STL–MIA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 12 minutes.
- Which airline is most reliable from STL to MIA?
- American Airlines has the best on-time record on this route at 88%, based on 1,060 flights. 3 airlines flew STL–MIA frequently enough to compare in this period.
- What is the best time of day to fly from STL to MIA?
- Departures around 5 a.m. have the best record (91% on-time), while departures around 5 p.m. have the worst (65%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from STL to MIA?
- The scheduled STL–MIA flight time averages 2h 47m over 1,068 miles. Actual arrival times vary — flights on this route land 15+ minutes late 18% of the time.
- How often are STL to MIA flights cancelled?
- 0.9% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from STL to MIA?
- December 2024 was the roughest month in this dataset, with only 71% of arrivals on time. The best was April 2026 at 94%. If your dates are flexible, that 23-point gap is worth planning around.
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Based on 2,252 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.