Best Time to Fly MIA to STL: On-Time Stats by Hour & Airline
Miami International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 74.0% of Miami (MIA) to St. Louis (STL) flights arrived on time (1,167 scheduled flights). That is 3.7 points below the national average of 77.6%.
Envoy Air was the most punctual of the 3 airlines on the route at 89.9%, while Southwest Airlines trailed at 69.3%.
November has been the best month (85% on time) and Sunday the weakest day of the week (64%).
0.7% of flights were cancelled, versus 1.8% nationally.
MIA to STL on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Envoy Air | 89.9% | 46 min | 0.0% | 119 |
| American Airlines | 74.2% | 74 min | 1.0% | 604 |
| Southwest Airlines | 69.3% | 53 min | 0.5% | 440 |
| Republic Airways | Limited data | 4 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly MIA to STL
On-time arrival % by scheduled departure hour (local time), 2,183 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 97.6% | 0.0% | 41 |
| 6am–7am | Limited data | 18 | |
| 7am–8am | 94.1% | 0.0% | 101 |
| 8am–9am | 90.8% | 0.0% | 165 |
| 9am–10am | Limited data | 10 | |
| 10am–11am | Limited data | 28 | |
| 11am–12pm | Limited data | 18 | |
| 12pm–1pm | 71.9% | 0.0% | 32 |
| 1pm–2pm | 83.8% | 0.0% | 38 |
| 2pm–3pm | 86.4% | 0.3% | 290 |
| 3pm–4pm | 73.1% | 1.9% | 307 |
| 4pm–5pm | 64.1% | 0.0% | 92 |
| 5pm–6pm | 70.3% | 0.8% | 119 |
| 6pm–7pm | 63.8% | 1.1% | 95 |
| 7pm–8pm | 32.4% | 0.0% | 68 |
| 8pm–9pm | 65.3% | 0.3% | 295 |
| 9pm–10pm | 73.8% | 1.6% | 315 |
| 10pm–11pm | 55.0% | 0.0% | 151 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on MIA to STL
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 68.0% | -7.7 pts | 0.0% | 51 |
| Christmas & New Year (Dec 20 - Jan 3) | 66.0% | -9.8 pts | 0.0% | 94 |
| Summer peak (Jun 15 - Aug 15) | 67.7% | -8.1 pts | 0.3% | 332 |
| All other days | 75.7% | — | 0.9% | 1,706 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).