Best Time to Fly PDX to ONT: On-Time Stats by Hour & Airline
Portland International → Ontario International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 83.8% of Portland (PDX) to Ontario (ONT) flights arrived on time (566 scheduled flights). That is 6.2 points above the national average of 77.6%.
Among 3 airlines, Alaska Airlines led with 84.8% on time and Frontier Airlines was last with 78.3%.
Over 24 months, Tuesday was the most reliable day (88% on time) and August the worst month (77%).
The cancellation rate was 0.5% (US average 1.8%).
PDX to ONT on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Alaska Airlines | 84.8% | 52 min | 0.7% | 444 |
| SkyWest Airlines | 82.3% | 49 min | 0.0% | 62 |
| Frontier Airlines | 78.3% | 61 min | 0.0% | 60 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly PDX to ONT
On-time arrival % by scheduled departure hour (local time), 1,182 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 7am–8am | 96.2% | 0.9% | 105 |
| 8am–9am | 91.3% | 1.7% | 119 |
| 9am–10am | 92.1% | 0.0% | 38 |
| 10am–11am | Limited data | 25 | |
| 11am–12pm | 82.7% | 0.0% | 52 |
| 12pm–1pm | Limited data | 28 | |
| 1pm–2pm | Limited data | 18 | |
| 2pm–3pm | 83.0% | 1.1% | 179 |
| 3pm–4pm | 84.8% | 0.0% | 33 |
| 4pm–5pm | 84.1% | 0.0% | 63 |
| 5pm–6pm | 82.0% | 0.0% | 122 |
| 6pm–7pm | Limited data | 16 | |
| 7pm–8pm | 82.0% | 1.8% | 113 |
| 8pm–9pm | 77.8% | 0.0% | 45 |
| 9pm–10pm | 82.1% | 1.3% | 226 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on PDX to ONT
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | Limited data | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 75.0% | -11.1 pts | 0.0% | 60 |
| Summer peak (Jun 15 - Aug 15) | 81.8% | -4.3 pts | 1.2% | 172 |
| All other days | 86.1% | — | 0.9% | 924 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).