Route on-time record
ONT to PDX: most on-time flights and the best time to fly
Ontario (Ontario International Airport) to Portland (Portland International Airport). 522 nonstop flights in Jun 2025 to May 2026, 88% arrived within 15 minutes and 0.6% were cancelled. The most reliable flight number was Alaska 544 at 7:00 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
ONT → PDX
Ontario to Portland: 522 nonstop flights a year
On time (12 months)
88%
Cancelled
0.6%
avg delay 8 min
Best time to leave
Before 9 AM
91% on time vs 78% noon to 3 PM
Most reliable airline
SkyWest
90% chance on time
Lowest nonstop fare seen in the next two months: $225 (Southwest 249 on 2026-10-27). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
#1 · Alaska 544
7:00 AM → 9:28 AM2h 28m nonstop
Local times, typical schedule. Last flown 2026-05-12.
93%
chance on time
- On time (history)
- 94%
- Cancelled
- 0.5%
- Avg arrival delay
- 5 min
- Arrived on time 94% of the time (188 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; Noon to 3 PM: 78%).
Moderate track record · 188 flights
Find Alaska 544 fares Opens this date on Aviasales#2 · SkyWest 3426 · sold as United Express, Delta Connection, American Eagle or Alaska
5:56 PM → 8:25 PM2h 29m nonstop
Local times, typical schedule. Last flown 2026-05-11.
93%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 0 min
- Arrived on time 100% of the time (12 flights, Jun 2025 to May 2026).
- Short track record (12 flights), so its score leans on the airline's record at this hour.
Limited track record · 12 flights
Find 5:56 PM flight fares Opens this date on Aviasales#3 · Alaska 341
6:08 PM → 8:33 PM2h 25m nonstop
Local times, typical schedule. Last flown 2026-03-16.
89%
chance on time
- On time (history)
- 91%
- Cancelled
- 0.0%
- Avg arrival delay
- 10 min
- Arrived on time 91% of the time (56 flights, Jun 2025 to May 2026).
- Never cancelled in 56 scheduled flights.
- 80% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (56 flights), so its score leans on the airline's record at this hour.
Limited track record · 56 flights
Find Alaska 341 fares Opens this date on Aviasales#4 · Alaska 1333
11:15 AM → 1:39 PM2h 24m nonstop
Local times, typical schedule. Last flown 2026-05-31.
85%
chance on time
- On time (history)
- 79%
- Cancelled
- 0.0%
- Avg arrival delay
- 9 min
- Arrived on time 79% of the time (19 flights, Jun 2025 to May 2026).
- Short track record (19 flights), so its score leans on the airline's record at this hour.
Limited track record · 19 flights
Find Alaska 1333 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)90%
62 flights · 92% on time as flown · 0.4% cancel
- Alaska Airlines89%
351 flights · 91% on time as flown · 0.8% cancel
- Frontier Airlines82%
109 flights · 77% on time as flown · 0.3% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM91%
260 flights · avg delay 6 min
- Noon to 3 PM78%
60 flights · avg delay 11 min
- 3 to 6 PM88%
117 flights · avg delay 10 min
- 6 to 9 PM86%
66 flights · avg delay 8 min
Best day: Saturday (90%). Worst: Thursday (84%).
Smarter routing
Nearby airports that run more on time
SNA → PDX 92% chance on time
John Wayne Orange County International Airport to Portland International Airport · 1,543 flights a year · 30 mi from your airports · yours: 88%
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Airline (crew, maintenance, boarding)41%
- Late-arriving aircraft38%
- Air traffic control and airport volume21%
Share of delay minutes by the cause airlines report to the US DOT.
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure
ONT to PDX questions
- What time of day is best to fly ONT to PDX?
- Before 9 AM: 91% of flights arrived on time, against 78% for departures noon to 3 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
- Which airline is most on time from ONT to PDX?
- SkyWest, with a season-adjusted 90% chance of operating and arriving on time over 62 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on ONT to PDX?
- October (79% on time); the best was April (92%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from ONT
- PDX to ONT (return)
- ONT to PHX 83%
- ONT to DEN 79%
- ONT to SEA 86%
- ONT to LAS 78%
- ONT to DFW 78%
- ONT to SMF 86%
- ONT to OAK 87%
- ONT to SJC 86%
- ONT to SFO 69%
- ONT to SLC 91%
- ONT to ATL 90%
- ONT to IAH 85%
Live status: FAA delays and ground stops