Best Time to Fly ORD to MIA: On-Time Stats by Hour & Airline
Chicago O'Hare International → Miami International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 74.0% of Chicago (ORD) to Miami (MIA) flights arrived on time (4,452 scheduled flights). That is 3.6 points below the national average of 77.6%.
American Airlines was the most punctual of the 4 airlines on the route at 75.6%, while Spirit Airlines trailed at 59.6%.
October has been the best month (87% on time) and Sunday the weakest day of the week (70%).
1.9% of flights were cancelled, versus 1.8% nationally.
ORD 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 | 75.6% | 75 min | 1.9% | 3,017 |
| United Airlines | 74.1% | 63 min | 0.8% | 1,071 |
| Frontier Airlines | 64.4% | 120 min | 2.2% | 46 |
| Spirit Airlines | 59.6% | 70 min | 6.6% | 318 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ORD to MIA
On-time arrival % by scheduled departure hour (local time), 8,801 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 12am–1am | Limited data | 3 | |
| 5am–6am | 91.8% | 1.0% | 729 |
| 6am–7am | 89.3% | 1.1% | 735 |
| 7am–8am | 85.5% | 0.9% | 1,043 |
| 8am–9am | 79.0% | 0.8% | 824 |
| 9am–10am | 75.1% | 1.3% | 314 |
| 10am–11am | 76.8% | 0.5% | 1,266 |
| 11am–12pm | 80.6% | 1.7% | 174 |
| 12pm–1pm | 75.8% | 1.0% | 482 |
| 1pm–2pm | 77.2% | 0.5% | 369 |
| 2pm–3pm | 68.1% | 0.8% | 497 |
| 3pm–4pm | 70.1% | 1.0% | 386 |
| 4pm–5pm | 55.8% | 3.2% | 411 |
| 5pm–6pm | 67.7% | 2.9% | 481 |
| 6pm–7pm | 63.0% | 3.8% | 584 |
| 7pm–8pm | 68.6% | 3.9% | 440 |
| 8pm–9pm | 76.3% | 2.6% | 39 |
| 9pm–10pm | Limited data | 24 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ORD 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) | 70.8% | -7.8 pts | 3.1% | 160 |
| Christmas & New Year (Dec 20 - Jan 3) | 70.4% | -8.2 pts | 0.7% | 415 |
| Summer peak (Jun 15 - Aug 15) | 69.9% | -8.7 pts | 1.8% | 1,357 |
| All other days | 78.6% | — | 1.4% | 6,869 |
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).