Best Time to Fly STL to MIA: On-Time Stats by Hour & Airline
St Louis Lambert International → Miami International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 82.2% of St. Louis (STL) to Miami (MIA) flights arrived on time (1,170 scheduled flights). That is 4.6 points above the national average of 77.6%.
Among 3 airlines, American Airlines led with 89.8% on time and Southwest Airlines was last with 72.0%.
Over 24 months, Wednesday was the most reliable day (90% on time) and December the worst month (75%).
The cancellation rate was 0.7% (US average 1.8%).
STL to MIA 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 |
|---|---|---|---|---|
| American Airlines | 89.8% | 98 min | 1.0% | 606 |
| Envoy Air | 83.0% | 45 min | 0.0% | 119 |
| Southwest Airlines | 72.0% | 43 min | 0.5% | 441 |
| Republic Airways | Limited data | 4 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly STL to MIA
On-time arrival % by scheduled departure hour (local time), 2,186 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 91.7% | 0.8% | 733 |
| 6am–7am | Limited data | 25 | |
| 7am–8am | 81.5% | 0.0% | 54 |
| 8am–9am | 83.6% | 0.9% | 227 |
| 9am–10am | 79.0% | 0.0% | 82 |
| 10am–11am | 79.3% | 1.1% | 89 |
| 11am–12pm | 86.6% | 0.4% | 234 |
| 12pm–1pm | 72.1% | 0.0% | 124 |
| 1pm–2pm | 70.7% | 2.6% | 77 |
| 2pm–3pm | Limited data | 25 | |
| 3pm–4pm | Limited data | 19 | |
| 4pm–5pm | 78.3% | 0.6% | 164 |
| 5pm–6pm | 64.5% | 0.0% | 62 |
| 6pm–7pm | 77.0% | 1.7% | 230 |
| 7pm–8pm | Limited data | 15 | |
| 8pm–9pm | Limited data | 26 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on STL to MIA
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) | 78.4% | -5.3 pts | 0.0% | 51 |
| Christmas & New Year (Dec 20 - Jan 3) | 76.6% | -7.1 pts | 0.0% | 94 |
| Summer peak (Jun 15 - Aug 15) | 78.8% | -4.9 pts | 0.6% | 332 |
| All other days | 83.7% | — | 1.0% | 1,709 |
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).