Route profile
MIA→STL
Flight reliability, delays and best times to fly from Miami to St. Louis, 1,068 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 28% of comparable major US routes (4,598 compared)
Calculated from 3,100 flights. How this is calculated · What counts as on time
MIA → STL arrives on time 72.8% of the time; the return trip, STL → MIA, arrives on time 81.3% of the time, an 8.5-point gap between the two directions of the same city pair.
MIA → STL spends 26.6 minutes on the ground on a 1,068-mile trip: 20.2 minutes from pushback to wheels-up at MIA and 6.4 minutes from touchdown to gate at STL.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route has stayed remarkably steady year over year, a smaller swing than 98% of 5,368 comparable routes.
74.0% on time over the most recent 12 months (2025-08 to 2026-07), against 73.9% in the 12 months before (2024-08 to 2025-07), virtually unchanged.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
What sets this route apart
Where MIA to STL differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
MIA to STL is at its best against routes of similar length for flights scheduled at 2 PM: 81.3% arrive on time, 8.3 points ahead of the 73.0% those routes manage at that hour. Against all other routes the gap is 6.7 points.
Sunday is the day MIA to STL slips furthest against routes of similar length, 64.9% on time where they average 73.2%, 8.3 points lower. Against all other routes the gap is 9.9 points.
In August, MIA to STL runs 12.4 points below routes of similar length, 61.9% on time to 74.3%. Against all other routes the gap is 14.6 points.
Southwest Airlines’ flights on MIA to STL arrive on time 71.1% of the time, 4.1 points below the 75.2% it manages on its routes of similar length. Against all other routes the gap is 6.3 points.
MIA to STL against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 2 PM departures | 81.3% | routes of similar length | 73.0% | +8.3 pts | 359 here, 177,087 there |
| Weekday: Sunday | 64.9% | routes of similar length | 73.2% | −8.3 pts | 484 here, 423,630 there |
| Month: August | 61.9% | routes of similar length | 74.3% | −12.4 pts | 176 here, 228,922 there |
| Airline: Southwest Airlines | 71.1% | routes of similar length | 75.2% | −4.1 pts | 1,259 here, 631,823 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,068 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
58 min late
against a median of 3 min early
MIA → STL has an average that understates its risk: a typical arrival is 3 min early, but the worst tenth are 61 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 3,100 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at STL after arriving from MIA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 44% | Likely to miss |
| 45 min | 26% | High risk |
| 60 min | 17% | High risk |
| 90 min | 9.7% | Some risk |
| 120 min | 5.9% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.81% of the time and diverts 0.26% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,067 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 58 minutes late (90th-percentile gate arrival delay), over 3,100 operations.
Any other layover length: connection checker.
Best time to fly
MIA → STL flights departing 5–9 AM arrived on time 92.8% of the time, against 57.7% for 6–9 PM departures, a gap of 35.1 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 93.9% on time from 131 flights
- 8 AM: 91.2% on time from 171 flights
- 9 AM to 12 PM: too few flights to score
- 1 PM: 78.5% on time from 147 flights
- 2 PM: 81.3% on time from 364 flights
- 3 PM: 69.1% on time from 428 flights
- 4 PM: too few flights to score
- 5 PM: 69.9% on time from 134 flights
- 6 PM to 7 PM: too few flights to score
- 8 PM: 63.4% on time from 307 flights
- 9 PM: 73.4% on time from 681 flights
- 10 PM: 57.2% on time from 181 flights
- 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why MIA → STL runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for MIA → STL. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on MIA → STL, at 49.0%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 92.8% of the time and 6–9 PM departures 57.7%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| American Airlines | 1,519 | 71.5% | 1.05% | -4 min | 11.3% |
| Southwest Airlines | 1,268 | 71.1% | 0.63% | -1 min | 9.8% |
| Envoy Air | 303 | 86.3% | 0.33% | -7 min | 3.3% |
American Airlines flew 49.2% of the 3,090 flights listed.
Envoy Air arrived on time 15.2 percentage points more often than Southwest Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| AA1594 American Airlines | 10:09 PM | 628 | 63.5% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 13.6 percentage points.
By month
- Jan: 75.3%
- Feb: 77.8%
- Mar: 72.8%
- Apr: 72.7%
- May: 66.9%
- Jun: 65.6%
- Jul: 68.1%
- Aug: 61.9%
- Sep: 70.7%
- Oct: 83.8%
- Nov: 86.8%
- Dec: 69.3%
August is historically the weakest month and November the strongest, a spread of 24.9 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: too few flights to score (46)
- August 2023: too few flights to score (41)
- September 2023: too few flights to score (39)
- October 2023: too few flights to score (59)
- November 2023: too few flights to score (64)
- December 2023: too few flights to score (82)
- January 2024: too few flights to score (93)
- February 2024: too few flights to score (95)
- March 2024: too few flights to score (107)
- April 2024: too few flights to score (69)
- May 2024: too few flights to score (88)
- June 2024: too few flights to score (68)
- July 2024: too few flights to score (66)
- August 2024: too few flights to score (64)
- September 2024: too few flights to score (60)
- October 2024: too few flights to score (67)
- November 2024: too few flights to score (89)
- December 2024: too few flights to score (94)
- January 2025: too few flights to score (96)
- February 2025: too few flights to score (88)
- March 2025: too few flights to score (106)
- April 2025: too few flights to score (99)
- May 2025: too few flights to score (102)
- June 2025: too few flights to score (77)
- July 2025: too few flights to score (74)
- August 2025: too few flights to score (73)
- September 2025: too few flights to score (68)
- October 2025: too few flights to score (84)
- November 2025: too few flights to score (105)
- December 2025: too few flights to score (98)
- January 2026: too few flights to score (110)
- February 2026: too few flights to score (110)
- March 2026: 78.9% from 136 flights
- April 2026: too few flights to score (96)
- May 2026: too few flights to score (89)
- June 2026: too few flights to score (98)
- July 2026: too few flights to score (100)
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 74.0% against 73.9% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 3,100 MIA → STL flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed