FlightRecord

Miami (MIA) to St. Louis (STL): On-Time Performance

Data through July 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 74% 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
74%
arrived <15 min late
Avg delay
18 min
completed flights
Cancelled
0.8%
Flights/day
3.2
last 12 months
Duration
3h 1m
scheduled
Distance
1,068 mi

Best airline from MIA to STL

3 airlines flew this route regularly between 2024-07 and 2026-07.

AirlineOn-timeAvg delayCancelledFlights
Envoy Airmost reliable88%7 min0.4%276
Southwest Airlines72%18 min0.5%912
American Airlines72%21 min1.0%1,057

Monthly on-time trend

Monthly on-time percentage for MIA to STL flights50%75%100%August 2024: 70% on-time (64 flights)70Aug 2024September 2024: 73% on-time (60 flights)73October 2024: 91% on-time (67 flights)91November 2024: 88% on-time (89 flights)88Nov 2024December 2024: 67% on-time (94 flights)67January 2025: 87% on-time (96 flights)87February 2025: 85% on-time (88 flights)85Feb 2025March 2025: 70% on-time (106 flights)70April 2025: 76% on-time (99 flights)76May 2025: 66% on-time (102 flights)66May 2025June 2025: 55% on-time (77 flights)55July 2025: 55% on-time (74 flights)55August 2025: 53% on-time (73 flights)53Aug 2025September 2025: 68% on-time (68 flights)68October 2025: 74% on-time (84 flights)74November 2025: 83% on-time (105 flights)83Nov 2025December 2025: 68% on-time (98 flights)68January 2026: 76% on-time (110 flights)76February 2026: 73% on-time (110 flights)73Feb 2026March 2026: 78% on-time (136 flights)78April 2026: 74% on-time (96 flights)74May 2026: 74% on-time (89 flights)74May 2026June 2026: 78% on-time (98 flights)78July 2026: 78% on-time (100 flights)78

Best time to fly from MIA to STL

Aim for departures around 5 a.m. (98% on-time); avoid 7 p.m. departures (32%).

On-time percentage by scheduled departure hour, MIA to STL5 a.m.: 98% on-time (41 flights)56 a.m.: 91% on-time (22 flights)67 a.m.: 94% on-time (101 flights)78 a.m.: 90% on-time (165 flights)810 a.m.: 85% on-time (28 flights)1012 p.m.: 75% on-time (36 flights)121 p.m.: 82% on-time (38 flights)132 p.m.: 85% on-time (301 flights)143 p.m.: 72% on-time (318 flights)154 p.m.: 64% on-time (92 flights)165 p.m.: 70% on-time (119 flights)176 p.m.: 64% on-time (100 flights)187 p.m.: 32% on-time (68 flights)198 p.m.: 65% on-time (295 flights)209 p.m.: 74% on-time (346 flights)2110 p.m.: 55% on-time (151 flights)22scheduled departure hour

By day of week

DayOn-timeAvg delay
Monday74%23 min
Tuesdaybest80%16 min
Wednesday79%12 min
Thursday73%18 min
Friday74%16 min
Saturday73%18 min
Sunday64%24 min

What causes delays on this route

Share of total delay minutes by cause, as reported by carriers to the US DOT.

  • Late-arriving aircraft50%
  • Airline operations30%
  • National airspace system15%
  • Weather4%

Frequently asked questions

How often are flights from MIA to STL delayed?
26% of MIA–STL 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 18 minutes.
Which airline is most reliable from MIA to STL?
Envoy Air has the best on-time record on this route at 88%, based on 276 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 (98% 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 26% of the time.
How often are MIA to STL flights cancelled?
0.8% 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 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.

Based on 2,249 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.