Portland (PDX) to Ontario (ONT): On-Time Performance
Data through July 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 85% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 82%), which matters most in the rough months.
- On-time
- 85%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 1.0%
- Flights/day
- 1.6
- last 12 months
- Duration
- 2h 20m
- scheduled
- Distance
- 838 mi
Best airline from PDX to ONT
3 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| SkyWest Airlinesmost reliable | 88% | 7 min | 1.1% | 275 |
| Alaska Airlines | 85% | 9 min | 0.9% | 693 |
| Frontier Airlines | 83% | 15 min | 1.1% | 264 |
Monthly on-time trend
Best time to fly from PDX to ONT
Aim for departures around 7 a.m. (96% on-time); avoid 8 p.m. departures (78%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 86% | 7 min |
| Tuesday | 87% | 6 min |
| Wednesday | 86% | 10 min |
| Thursday | 85% | 12 min |
| Friday | 82% | 16 min |
| Saturdaybest | 87% | 7 min |
| Sunday | 83% | 10 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft42%
- Airline operations47%
- National airspace system11%
Frequently asked questions
- How often are flights from PDX to ONT delayed?
- 15% of PDX–ONT 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 10 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 275 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 (96% on-time), while departures around 8 p.m. have the worst (78%). 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 15% of the time.
- How often are PDX to ONT flights cancelled?
- 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 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.
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Based on 1,249 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.