Route profile
PDX→ONT
Flight reliability, delays and best times to fly from Portland to Ontario, 838 miles.
Right now
Weather conditions are strongly associated with delays and cancellations.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 80% of comparable major US routes (4,598 compared)
Calculated from 1,777 flights. How this is calculated
PDX → ONT arrives on time 85.3% of the time; the return trip, ONT → PDX, arrives on time 87.7% of the time, a 2.4-point gap between the two directions of the same city pair.
PDX → ONT spends 20.4 minutes on the ground on an 838-mile trip: 15.3 minutes from pushback to wheels-up at PDX and 5.2 minutes from touchdown to gate at ONT.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route stays close to typical even on its worst days, a smaller gap than 94% of 4,598 comparable routes.
A typical arrival is 5 min early, and the worst tenth are only 29 minutes worse than that.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,598 in the comparison.
What sets this route apart
Where PDX to ONT differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
PDX to ONT is at its best against routes of similar length for flights scheduled at 7 PM: 84.6% arrive on time, 17.5 points ahead of the 67.1% those routes manage at that hour. Against all other routes the gap is 16.8 points.
PDX to ONT holds up on Mondays better than routes of similar length do: 87.5% on time to their 76.8%, a 10.7 points lead. Against all other routes the gap is 10.3 points.
July is kinder to PDX to ONT than to routes of similar length: 85.3% on time against 68.2%, 17.1 points better. Against all other routes the gap is 15.6 points.
PDX to ONT against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 7 PM departures | 84.6% | routes of similar length | 67.1% | +17.5 pts | 208 here, 150,860 there |
| Weekday: Monday | 87.5% | routes of similar length | 76.8% | +10.7 pts | 281 here, 371,563 there |
| Month: July | 85.3% | routes of similar length | 68.2% | +17.1 pts | 156 here, 276,627 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 838 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
24 min late
against a median of 5 min early
Percentiles over 1,777 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at ONT after arriving from PDX.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 34% | Likely to miss |
| 45 min | 14% | Some risk |
| 60 min | 8.5% | Some risk |
| 90 min | 4.5% | Low risk |
| 120 min | 2.2% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.52% of the time and diverts 0.17% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,747 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 24 minutes late (90th-percentile gate arrival delay), over 1,777 operations.
Any other layover length: connection checker.
Best time to fly
PDX → ONT flights departing 5–9 AM arrived on time 93.3% of the time, against 82.1% for 9 PM–5 AM departures, a gap of 11.2 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 95.3% on time from 130 flights
- 8 AM: 91.7% on time from 173 flights
- 9 AM to 1 PM: too few flights to score
- 2 PM: 83.2% on time from 188 flights
- 3 PM: 81.1% on time from 144 flights
- 4 PM: 83.4% on time from 151 flights
- 5 PM: 84.6% on time from 223 flights
- 6 PM: too few flights to score
- 7 PM: 84.6% on time from 210 flights
- 8 PM: too few flights to score
- 9 PM: 82.1% on time from 226 flights
- 10 PM to 11 PM: too few flights to score
Why PDX → ONT runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for PDX → ONT. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on PDX → ONT, at 47.0%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 93.3% of the time and 9 PM–5 AM departures 82.1%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Alaska Airlines | 868 | 84.3% | 2.07% | -4 min | 3.9% |
| SkyWest Airlines | 514 | 89.6% | 0.58% | -6 min | 3.9% |
| Frontier Airlines | 346 | 82.9% | 1.73% | -7 min | 6.5% |
Alaska Airlines flew 50.2% of the 1,728 flights listed. Alaska Airlines cancelled 2.07% of its flights here against 0.58% for SkyWest Airlines.
SkyWest Airlines arrived on time 6.7 percentage points more often than Frontier Airlines on this route.
Other ways to fly Portland to Los Angeles
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| PDX→LAX Portland to Los Angeles | 13,548 | 87.8% | 0.85% | -10 min | 84 |
| PDX→ONT this route Portland to Ontario | 1,777 | 85.3% | 1.52% | -5 min | 77 |
PDX → LAX is the most reliable pairing for this journey at 87.8% on time, against 85.3% for PDX → ONT.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Friday the least, a gap of 4.8 percentage points.
By month
- Jan: 83.0%
- Feb: 86.4%
- Mar: 91.9%
- Apr: 87.9%
- May: 90.4%
- Jun: 84.5%
- Jul: 85.3%
- Aug: 75.5%
- Sep: 84.2%
- Oct: 90.5%
- Nov: 84.8%
- Dec: 79.2%
August is historically the weakest month and March the strongest, a spread of 16.4 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 83.8% against 86.0% in the 12 months before — declining by 2.2 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,777 PDX → ONT flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed