Best Time to Fly ONT to PDX: On-Time Stats by Hour & Airline
Ontario International → Portland International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 90.2% of Ontario (ONT) to Portland (PDX) flights arrived on time (565 scheduled flights). That is 12.6 points above the national average of 77.6%.
Alaska Airlines was the most punctual of the 3 airlines on the route at 92.0%, while Frontier Airlines trailed at 75.0%.
April has been the best month (97% on time) and Thursday the weakest day of the week (85%).
0.7% of flights were cancelled, versus 1.8% nationally.
ONT to PDX 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 | 92.0% | 73 min | 0.9% | 443 |
| SkyWest Airlines | 91.9% | 66 min | 0.0% | 62 |
| Frontier Airlines | 75.0% | 34 min | 0.0% | 60 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ONT to PDX
On-time arrival % by scheduled departure hour (local time), 1,183 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 97.1% | 0.0% | 34 |
| 7am–8am | 95.3% | 1.2% | 408 |
| 8am–9am | 79.5% | 0.0% | 44 |
| 9am–10am | Limited data | 2 | |
| 10am–11am | 94.7% | 0.9% | 115 |
| 11am–12pm | 89.8% | 0.8% | 119 |
| 12pm–1pm | Limited data | 15 | |
| 1pm–2pm | Limited data | 11 | |
| 2pm–3pm | 77.6% | 0.0% | 67 |
| 3pm–4pm | 78.8% | 0.0% | 33 |
| 4pm–5pm | Limited data | 8 | |
| 5pm–6pm | 91.6% | 0.8% | 120 |
| 6pm–7pm | 78.0% | 1.6% | 125 |
| 7pm–8pm | 78.7% | 0.0% | 61 |
| 8pm–9pm | Limited data | 21 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ONT to PDX
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) | 78.0% | -11.4 pts | 0.0% | 59 |
| Summer peak (Jun 15 - Aug 15) | 86.6% | -2.8 pts | 0.6% | 173 |
| All other days | 89.4% | — | 1.0% | 925 |
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).