Best Time to Fly MIA to ORD: On-Time Stats by Hour & Airline
Miami International → Chicago O'Hare International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 71.2% of Miami (MIA) to Chicago (ORD) flights arrived on time (4,450 scheduled flights). That is 6.5 points below the national average of 77.6%.
Among 4 airlines, Frontier Airlines led with 73.3% on time and Spirit Airlines was last with 63.0%.
Over 24 months, Tuesday was the most reliable day (81% on time) and July the worst month (59%).
The cancellation rate was 2.0% (US average 1.8%).
MIA to ORD 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 |
|---|---|---|---|---|
| Frontier Airlines | 73.3% | 175 min | 2.2% | 46 |
| American Airlines | 72.3% | 76 min | 1.9% | 3,017 |
| United Airlines | 70.2% | 86 min | 1.0% | 1,070 |
| Spirit Airlines | 63.0% | 63 min | 6.6% | 317 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly MIA to ORD
On-time arrival % by scheduled departure hour (local time), 8,796 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 86.8% | 6.9% | 58 |
| 6am–7am | 90.5% | 2.0% | 716 |
| 7am–8am | 87.1% | 0.0% | 359 |
| 8am–9am | 89.5% | 1.0% | 711 |
| 9am–10am | 86.1% | 0.6% | 670 |
| 10am–11am | 61.9% | 0.0% | 63 |
| 11am–12pm | 83.5% | 0.0% | 159 |
| 12pm–1pm | 81.3% | 0.6% | 786 |
| 1pm–2pm | 76.6% | 1.6% | 514 |
| 2pm–3pm | 70.9% | 1.9% | 369 |
| 3pm–4pm | 63.8% | 1.7% | 716 |
| 4pm–5pm | 60.6% | 1.4% | 1,031 |
| 5pm–6pm | 57.8% | 1.8% | 623 |
| 6pm–7pm | 55.4% | 1.0% | 386 |
| 7pm–8pm | 68.8% | 0.7% | 443 |
| 8pm–9pm | 66.0% | 2.8% | 424 |
| 9pm–10pm | 75.9% | 2.5% | 566 |
| 10pm–11pm | 74.6% | 3.0% | 200 |
| 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 MIA to ORD
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) | 74.0% | -2.2 pts | 3.8% | 160 |
| Christmas & New Year (Dec 20 - Jan 3) | 76.2% | -0.0 pts | 0.5% | 414 |
| Summer peak (Jun 15 - Aug 15) | 62.3% | -13.9 pts | 1.8% | 1,356 |
| All other days | 76.2% | — | 1.3% | 6,866 |
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).