PDX to SEA flight delays
Portland, OR (PDX) Seattle, WA (SEA) · 129 miles
4,938 flights · January 2025 – August 2026 · US Bureau of Transportation Statistics
84.81%
Arrived on time
Within 15 minutes of schedule
0.65%
Cancelled
Share of scheduled flights
55 min
When late, late by
Average across delayed arrivals
9 min
Delay per flight
Averaged over every flight flown
What the record says about this route
Flights from Portland to Seattle keep to schedule more reliably than most. On a route this punctual the day you fly matters more than the airline you pick.
The 3 airlines here are separated by under 6 points — close enough to call a tie. Choose on price and departure time.
Which airline should you fly on this route?
Over January 2025 – August 2026, Delta Air Lines arrived on time most often on PDX to SEA. Alaska Airlines was late most often. Flights ran closest to schedule in February and worst in July.
Every airline on PDX to SEA
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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 3,501 | 85.24% | 0.54% | 59 min | B |
| Alaska Airlines | 1,125 | 82.64% | 1.16% | 42 min | B |
| Delta Air Lines | 312 | 87.82% | 0% | 61 min | A |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
SEA to PDX Seattle back to Portland 83.12% on time BOther routes from Portland
Common questions
Are flights from Portland to Seattle usually delayed?
84.81% of flights on the PDX to SEA 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 airline is most on time from Portland to Seattle?
Delta Air Lines, at 87.82% on time across 312 flights. The least punctual on the route was Alaska Airlines at 82.64%.
How often are PDX to SEA flights cancelled?
0.65% of scheduled flights did not operate — about 7 in every thousand. That is in the normal range.
What is the best month to fly Portland to Seattle?
February, when 91.2% of flights arrived on time. The worst was July at 75.9%.
When PDX to SEA flights are late, how late are they?
About 55 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 SEA 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 →