Best Time to Fly IAH to MIA: On-Time Stats by Hour & Airline
George Bush Intercontinental/Houston → Miami International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 78.2% of Houston (IAH) to Miami (MIA) flights arrived on time (3,712 scheduled flights). That is 0.5 points above the national average of 77.6%.
Among 5 airlines, United Airlines led with 81.7% on time and Frontier Airlines was last with 67.9%.
Over 24 months, Tuesday was the most reliable day (83% on time) and July the worst month (68%).
The cancellation rate was 1.1% (US average 1.8%).
IAH 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 |
|---|---|---|---|---|
| United Airlines | 81.7% | 60 min | 0.2% | 1,469 |
| Envoy Air | 78.5% | 52 min | 0.0% | 122 |
| American Airlines | 78.0% | 109 min | 1.3% | 1,552 |
| Spirit Airlines | 70.1% | 81 min | 3.2% | 380 |
| Frontier Airlines | 67.9% | 160 min | 4.0% | 175 |
| Republic Airways | Limited data | 14 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAH to MIA
On-time arrival % by scheduled departure hour (local time), 7,365 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 12am–1am | Limited data | 2 | |
| 5am–6am | 89.5% | 1.7% | 766 |
| 6am–7am | 87.2% | 0.0% | 87 |
| 7am–8am | 85.8% | 1.2% | 1,446 |
| 8am–9am | 87.1% | 0.0% | 31 |
| 9am–10am | 80.0% | 1.6% | 320 |
| 10am–11am | 77.7% | 0.0% | 177 |
| 11am–12pm | 77.3% | 0.7% | 581 |
| 12pm–1pm | 78.4% | 0.8% | 793 |
| 1pm–2pm | Limited data | 28 | |
| 2pm–3pm | 71.0% | 0.0% | 342 |
| 3pm–4pm | 71.3% | 0.8% | 123 |
| 4pm–5pm | 70.5% | 2.1% | 580 |
| 5pm–6pm | 63.5% | 2.9% | 345 |
| 6pm–7pm | 69.2% | 1.3% | 1,247 |
| 7pm–8pm | 70.9% | 0.9% | 223 |
| 8pm–9pm | 62.3% | 5.7% | 211 |
| 9pm–10pm | 86.0% | 0.0% | 50 |
| 10pm–11pm | Limited data | 11 | |
| 11pm–12am | Limited data | 2 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAH 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) | 82.2% | +3.7 pts | 0.7% | 153 |
| Christmas & New Year (Dec 20 - Jan 3) | 68.7% | -9.9 pts | 1.3% | 318 |
| Summer peak (Jun 15 - Aug 15) | 71.7% | -6.9 pts | 2.3% | 1,205 |
| All other days | 78.6% | — | 1.2% | 5,689 |
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).