PDX to ONT flight delays
Portland, OR (PDX) Ontario, CA (ONT) · 838 miles
552 flights · January 2025 – August 2026 · US Bureau of Transportation Statistics
83.97%
Arrived on time
Within 15 minutes of schedule
0.36%
Cancelled
Share of scheduled flights
54 min
When late, late by
Average across delayed arrivals
10 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In October it ran 21.8 points more punctual than in December — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.
The two directions do not behave alike. ONT to PDX arrives on time 5.1 points more often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
Only Alaska Airlines flies this route in the published record, so there is no choice to weigh — the route's figures and the airline's are the same figures.
This is a thin route — 552 flights across the whole period. On a route this infrequent a cancellation is far more costly than the rate suggests, because the next departure may not be the same day.
Which airline should you fly on this route?
Over January 2025 – August 2026, Alaska Airlines arrived on time most often on PDX to ONT. Flights ran closest to schedule in October and worst in December.
Every airline on PDX to ONT
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Alaska Airlines | 404 | 84.79% | 0.5% | 54 min | B |
| Frontier Airlines | 86 | 81.4% | 0% | 57 min | — |
| SkyWest Airlines | 62 | 82.26% | 0% | 49 min | — |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
ONT to PDX Ontario back to Portland 89.03% on time AOther routes from Portland
Common questions
Are flights from Portland to Ontario usually delayed?
83.97% of flights on the PDX to ONT route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is better than the average route in this record.
Which airlines fly from Portland to Ontario?
Only Alaska Airlines appears in the published record on this route, with 404 flights and 84.79% arriving on time.
How often are PDX to ONT flights cancelled?
0.36% of scheduled flights did not operate — about 4 in every thousand. That is in the normal range.
What is the best month to fly Portland to Ontario?
October, when 90.7% of flights arrived on time. The worst was December at 68.9%.
When PDX to ONT flights are late, how late are they?
About 54 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on PDX to ONT during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →