About 1 in 5 AS 3431 flights from Portland arrived 15+ minutes late, diverted or cancelled over the past year (19%); 0.0% were cancelled. The typical flight landed 2 minutes early.
AS 3431: PDX → SEA
Scheduled to leave Portland at 10:35 a.m. local time, operated by SkyWest as OO 3431. Over the past year it arrived on time 81% of the time (151 flights), worse than other AS flights on the route at that hour (85%). Last seen in the data Aug 18, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 22 | 82% |
| Tuesday | 22 | 77% |
| Wednesday | 22 | 77% |
| Thursday | 22 | 77% |
| Friday | 21 | 90% |
| Saturday | 21 | 95% |
| Sunday | 21 | 67% |
Why it was late
All flights PDX → SEA · Connecting off AS 3431? Check the risk
Questions
How often is AS 3431 from PDX to SEA late?
Alaska Airlines 3431 from Portland, OR to Seattle, WA arrived 15 or more minutes late, was diverted or was cancelled on 19% of 151 scheduled flights between September 2025 and August 2026. 0.0% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Alaska Airlines for today's flight. Method.