Best Time to Fly MDW to ONT: On-Time Stats by Hour & Airline
Chicago Midway International → Ontario International
Data through July 2026 · Last updated October 18, 2026
360 flights were scheduled from Chicago (MDW) to Ontario (ONT) in the last 12 months, and 70.2% of those that flew arrived on time, 7.4 points below the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
November has been the best month (93% on time) and Sunday the weakest day of the week (68%).
1.1% of flights were cancelled, versus 1.8% nationally.
MDW to ONT 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 |
|---|---|---|---|---|
| Southwest Airlines | 70.2% | 52 min | 1.1% | 360 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly MDW to ONT
On-time arrival % by scheduled departure hour (local time), 723 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 7am–8am | Limited data | 17 | |
| 8am–9am | 88.3% | 0.0% | 137 |
| 9am–10am | 93.3% | 0.0% | 60 |
| 10am–11am | 80.3% | 0.0% | 71 |
| 11am–12pm | 68.3% | 1.0% | 102 |
| 12pm–1pm | 90.7% | 0.0% | 54 |
| 1pm–2pm | 85.1% | 0.0% | 47 |
| 2pm–3pm | Limited data | 18 | |
| 3pm–4pm | 48.7% | 0.0% | 39 |
| 4pm–5pm | Limited data | 6 | |
| 5pm–6pm | 80.0% | 0.0% | 40 |
| 7pm–8pm | 75.0% | 3.0% | 33 |
| 8pm–9pm | 53.9% | 1.5% | 66 |
| 9pm–10pm | Limited data | 25 | |
| 10pm–11pm | Limited data | 8 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on MDW to ONT
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) | Limited data | 14 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 56.7% | -23.9 pts | 0.0% | 30 |
| Summer peak (Jun 15 - Aug 15) | 60.0% | -20.5 pts | 0.0% | 125 |
| All other days | 80.5% | — | 0.7% | 554 |
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).