Ontario (ONT) to Oakland (OAK): On-Time Performance
Data through July 2026
Ontario (ONT) to Oakland (OAK) effectively runs on two schedules. In March 2026, 97% of arrivals were on time; in June 2026 that fell to 76% — a 21-point seasonal swing. Across the full period the route averages 88% on-time against a national 78%. Morning departures also hold up better than evening ones (95% vs 81%), which matters most in the rough months.
- On-time
- 88%
- arrived <15 min late
- Avg delay
- 7 min
- completed flights
- Cancelled
- 0.4%
- Flights/day
- 4.0
- last 12 months
- Duration
- 1h 20m
- scheduled
- Distance
- 362 mi
Monthly on-time trend
Best time to fly from ONT to OAK
Aim for departures around 7 a.m. (97% on-time); avoid 9 p.m. departures (74%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 90% | 6 min |
| Tuesdaybest | 93% | 5 min |
| Wednesday | 90% | 7 min |
| Thursday | 89% | 7 min |
| Friday | 86% | 8 min |
| Saturday | 91% | 6 min |
| Sunday | 81% | 13 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft69%
- Airline operations28%
- National airspace system3%
Frequently asked questions
- How often are flights from ONT to OAK delayed?
- 12% of ONT–OAK 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 7 minutes.
- What is the best time of day to fly from ONT to OAK?
- Departures around 7 a.m. have the best record (97% on-time), while departures around 9 p.m. have the worst (74%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from ONT to OAK?
- The scheduled ONT–OAK flight time averages 1h 20m over 362 miles. Actual arrival times vary — flights on this route land 15+ minutes late 12% of the time.
- How often are ONT to OAK flights cancelled?
- 0.4% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from ONT to OAK?
- June 2026 was the roughest month in this dataset, with only 76% of arrivals on time. The best was March 2026 at 97%. If your dates are flexible, that 21-point gap is worth planning around.
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Based on 3,180 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.