FlightRecord

Chicago (MDW) to Ontario (ONT): On-Time Performance

Data through May 2026

Chicago (MDW) to Ontario (ONT) is a thinner route than most in this dataset — 360 departures over the past year, roughly 7 a week — so treat these numbers as indicative rather than definitive. Of the flights that did operate, 77% arrived on time.

On-time
77%
arrived <15 min late
Avg delay
14 min
completed flights
Cancelled
0.7%
Flights/day
0.99
last 12 months
Duration
4h 17m
scheduled
Distance
1,706 mi

Monthly on-time trend

Monthly on-time percentage for MDW to ONT flights50%75%100%June 2024: 60% on-time (30 flights)60Jun 2024July 2024: 81% on-time (31 flights)81August 2024: 85% on-time (34 flights)85September 2024: 88% on-time (34 flights)88Sep 2024October 2024: 90% on-time (31 flights)90November 2024: 89% on-time (28 flights)89December 2024: 72% on-time (29 flights)72Dec 2024January 2025: 86% on-time (28 flights)86February 2025: 96% on-time (26 flights)96March 2025: 87% on-time (31 flights)87Mar 2025April 2025: 83% on-time (30 flights)83May 2025: 81% on-time (31 flights)81June 2025: 63% on-time (30 flights)63Jun 2025July 2025: 58% on-time (31 flights)58August 2025: 70% on-time (31 flights)70September 2025: 77% on-time (30 flights)77Sep 2025October 2025: 74% on-time (31 flights)74November 2025: 96% on-time (30 flights)96December 2025: 65% on-time (31 flights)65Dec 2025January 2026: 78% on-time (27 flights)78February 2026: 89% on-time (27 flights)89March 2026: 67% on-time (31 flights)67Mar 2026April 2026: 73% on-time (30 flights)73May 2026: 52% on-time (31 flights)52

Best time to fly from MDW to ONT

Aim for departures around 9 a.m. (93% on-time); avoid 3 p.m. departures (50%).

On-time percentage by scheduled departure hour, MDW to ONT8 a.m.: 88% on-time (137 flights)89 a.m.: 93% on-time (60 flights)910 a.m.: 80% on-time (70 flights)1011 a.m.: 69% on-time (74 flights)1112 p.m.: 93% on-time (56 flights)121 p.m.: 85% on-time (47 flights)132 p.m.: 71% on-time (59 flights)143 p.m.: 50% on-time (32 flights)155 p.m.: 80% on-time (40 flights)177 p.m.: 75% on-time (33 flights)198 p.m.: 54% on-time (66 flights)209 p.m.: 54% on-time (25 flights)21scheduled departure hour

By day of week

DayOn-timeAvg delay
Monday79%11 min
Tuesday75%21 min
Wednesday81%11 min
Thursdaybest85%11 min
Friday74%14 min
Saturday78%10 min
Sunday70%18 min

What causes delays on this route

Share of total delay minutes by cause, as reported by carriers to the US DOT.

  • Late-arriving aircraft45%
  • Airline operations39%
  • National airspace system12%
  • Weather5%

Frequently asked questions

How often are flights from MDW to ONT delayed?
23% of MDW–ONT flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 14 minutes.
What is the best time of day to fly from MDW to ONT?
Departures around 9 a.m. have the best record (93% on-time), while departures around 3 p.m. have the worst (50%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
How long is the flight from MDW to ONT?
The scheduled MDW–ONT flight time averages 4h 17m over 1,706 miles. Actual arrival times vary — flights on this route land 15+ minutes late 23% of the time.
How often are MDW to ONT flights cancelled?
0.7% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
What is the worst month to fly from MDW to ONT?
May 2026 was the roughest month in this dataset, with only 52% of arrivals on time. The best was November 2025 at 96%. If your dates are flexible, that 45-point gap is worth planning around.

Explore related pages

More routes from MDW

Based on 723 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.