PDX → SEA: 83% on-time

Historical on-time performance

Portland to Seattle

129 miData through May 2026Source: US DOT · BTS

Flights on PDX–SEA arrive on time 83% of the time over the last 12 months.

On-time rate83%arrived within 15 min

p90 delay25 min1 in 10 flights is worse (tail risk)

Cancelled0.7%of scheduled flights

based on 4,870 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Too close to call — no single carrier is clearly more on-time here.

Airline	On-time	Median	p90	Cancel	Flights
Delta Air Lines	87%	on time	15 min	0.0%	275
SkyWest Airlines	84%	on time	25 min	0.5%	3,492
Alaska Airlines	81%	on time	25 min	1.3%	1,103

Delta Air Lines
On-time87%
Medianon time
p9015 min
Cancel0.0%
Flights275
SkyWest Airlines
On-time84%
Medianon time
p9025 min
Cancel0.5%
Flights3,492
Alaska Airlines
On-time81%
Medianon time
p9025 min
Cancel1.3%
Flights1,103

Why flights run late

Delay causes

Airline43%
Weather10%
Air traffic (NAS)19%
Late aircraft27%
Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

Airline24%
Weather27%
Air traffic (NAS)48%
Security0%

Most cancellations here are attributed to Air traffic (NAS). Shares are among 33 cancellations with a reported cause (BTS reports causes from June 2003).

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly PDX → SEA

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

Mornings are the most reliable time of day to fly this route — 89% on time.

Mornings89% on time · p90 10 min · 6,511 flights
Middays84% on time · p90 25 min · 3,910 flights
Afternoons83% on time · p90 25 min · 2,270 flights
Evenings81% on time · p90 25 min · 2,828 flights
Overnights80% on time · p90 30 min · 613 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 83% to 87% on time.

Saturdays87% on time · p90 15 min · 2,035 flights
Tuesdays87% on time · p90 20 min · 2,332 flights
Wednesdays86% on time · p90 20 min · 2,356 flights
Mondays86% on time · p90 20 min · 2,369 flights
Thursdays84% on time · p90 20 min · 2,390 flights
Sundays84% on time · p90 20 min · 2,297 flights
Fridays83% on time · p90 25 min · 2,353 flights

Keep exploring

Delay predictorfor this route→PDX airportPortland→SEA airportSeattle→SkyWest Airlinesairline profile→Alaska Airlinesairline profile→Delta Air Linesairline profile→Seasonal delay patternsguide→