Portland (PDX) to Ontario (ONT): On-Time Performance
Data through May 2026
The calendar drives reliability on PDX–ONT. March 2025 flights landed on schedule 98% of the time, but December 2025 dropped to 69% — a gap of 29 points. Across the full period the route averages 84% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 81%), which matters most in the rough months.
- On-time
- 84%
- arrived <15 min late
- Avg delay
- 11 min
- completed flights
- Cancelled
- 1.1%
- Flights/day
- 1.4
- last 12 months
- Duration
- 2h 20m
- scheduled
- Distance
- 838 mi
Best airline from PDX to ONT
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| SkyWest Airlinesmost reliable | 88% | 7 min | 1.0% | 310 |
| Alaska Airlines | 84% | 10 min | 0.8% | 601 |
| Frontier Airlines | 82% | 15 min | 1.7% | 294 |
Monthly on-time trend
Best time to fly from PDX to ONT
Aim for departures around 7 a.m. (100% on-time); avoid 8 p.m. departures (75%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 86% | 7 min |
| Tuesdaybest | 87% | 6 min |
| Wednesday | 84% | 10 min |
| Thursday | 84% | 13 min |
| Friday | 83% | 16 min |
| Saturday | 87% | 7 min |
| Sunday | 81% | 12 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft46%
- Airline operations45%
- National airspace system9%
Frequently asked questions
- How often are flights from PDX to ONT delayed?
- 16% of PDX–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 11 minutes.
- Which airline is most reliable from PDX to ONT?
- SkyWest Airlines has the best on-time record on this route at 88%, based on 310 flights. 3 airlines flew PDX–ONT frequently enough to compare in this period.
- What is the best time of day to fly from PDX to ONT?
- Departures around 7 a.m. have the best record (100% on-time), while departures around 8 p.m. have the worst (75%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from PDX to ONT?
- The scheduled PDX–ONT flight time averages 2h 20m over 838 miles. Actual arrival times vary — flights on this route land 15+ minutes late 16% of the time.
- How often are PDX to ONT flights cancelled?
- 1.1% 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 PDX to ONT?
- December 2025 was the roughest month in this dataset, with only 69% of arrivals on time. The best was March 2025 at 98%. If your dates are flexible, that 29-point gap is worth planning around.
Explore related pages
More routes from PDX
Other ways to fly to Ontario (ONT)
Related guides
Based on 1,227 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.