Ontario (ONT) to Chicago (ORD): On-Time Performance
Data through July 2026
Ontario (ONT) to Chicago (ORD) is a thinner route than most in this dataset — 291 departures over the past year, roughly 6 a week — so treat these numbers as indicative rather than definitive. Of the flights that did operate, 80% arrived on time.
- On-time
- 80%
- arrived <15 min late
- Avg delay
- 15 min
- completed flights
- Cancelled
- 1.1%
- Flights/day
- 0.80
- last 12 months
- Duration
- 4h 4m
- scheduled
- Distance
- 1,700 mi
Monthly on-time trend
Best time to fly from ONT to ORD
Aim for departures around 6 a.m. (84% on-time); avoid 11 p.m. departures (79%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 85% | 12 min |
| Tuesday | 78% | 19 min |
| Wednesdaybest | 86% | 17 min |
| Thursday | 79% | 10 min |
| Friday | 80% | 12 min |
| Saturday | 82% | 19 min |
| Sunday | 69% | 16 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft16%
- Airline operations45%
- National airspace system39%
Frequently asked questions
- How often are flights from ONT to ORD delayed?
- 20% of ONT–ORD flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 15 minutes.
- What is the best time of day to fly from ONT to ORD?
- Departures around 6 a.m. have the best record (84% on-time), while departures around 11 p.m. have the worst (79%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from ONT to ORD?
- The scheduled ONT–ORD flight time averages 4h 4m over 1,700 miles. Actual arrival times vary — flights on this route land 15+ minutes late 20% of the time.
- How often are ONT to ORD flights cancelled?
- 1.1% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What day of the week is most reliable for ONT to ORD?
- Wednesday flights have the best record at 86% on-time. Day-of-week differences on this route are meaningful — Sunday trails at 69%.
Explore related pages
More routes from ONT
Other ways to fly to Chicago (ORD)
Related guides
Based on 362 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.