Portland (PDX) to Seattle (SEA): On-Time Performance
Data through May 2026
When you fly PDX to SEA matters as much as anything else about the booking: the route swung from 93% on-time in November 2024 to just 75% in June 2025. Across the full period the route averages 85% on-time against a national 78%.
- On-time
- 85%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 0.6%
- Flights/day
- 14
- last 12 months
- Duration
- 1h 6m
- scheduled
- Distance
- 129 mi
Best airline from PDX to SEA
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 92% | 9 min | 0.4% | 748 |
| SkyWest Airlines | 84% | 10 min | 0.4% | 6,490 |
| Alaska Airlines | 84% | 9 min | 1.0% | 2,696 |
Monthly on-time trend
Best time to fly from PDX to SEA
Aim for departures around 5 a.m. (94% on-time); avoid 6 p.m. departures (70%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 84% | 10 min |
| Tuesdaybest | 88% | 8 min |
| Wednesday | 85% | 10 min |
| Thursday | 83% | 10 min |
| Friday | 83% | 10 min |
| Saturday | 87% | 9 min |
| Sunday | 85% | 10 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft23%
- Airline operations46%
- National airspace system18%
- Weather13%
Frequently asked questions
- How often are flights from PDX to SEA delayed?
- 15% of PDX–SEA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 10 minutes.
- Which airline is most reliable from PDX to SEA?
- Delta Air Lines has the best on-time record on this route at 92%, based on 748 flights. 3 airlines flew PDX–SEA frequently enough to compare in this period.
- What is the best time of day to fly from PDX to SEA?
- Departures around 5 a.m. have the best record (94% on-time), while departures around 6 p.m. have the worst (70%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from PDX to SEA?
- The scheduled PDX–SEA flight time averages 1h 6m over 129 miles. Actual arrival times vary — flights on this route land 15+ minutes late 15% of the time.
- How often are PDX to SEA flights cancelled?
- 0.6% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from PDX to SEA?
- June 2025 was the roughest month in this dataset, with only 75% of arrivals on time. The best was November 2024 at 93%. If your dates are flexible, that 18-point gap is worth planning around.
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Based on 9,934 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.