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Route · PDX → SEA · 2020–2025 BTS data

Portland to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), PDX to SEA (Portland to Seattle) ranks #57 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

87.7%
On-time
+8.7 pts
vs US avg
65 min
Delay when late
36,148
Flights
#57 of 4927
Corpus placement

Cancelled

1.0%

Best Month

Nov 2024 93%

Worst Month

Jun 2025 75%

Distance

129 mi

Carriers

19

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 412 81 2 0 DL,AS,OO
Nov 2025 441 46 15 0 OO,DL,AS
Oct 2025 458 54 2 0 AS,OO,DL
Sep 2025 463 76 0 0 OO,DL,AS
Aug 2025 444 86 2 0 OO,AS,DL
Jul 2025 423 102 0 0 AS,DL,OO
Jun 2025 403 99 1 0 AS,OO,DL
May 2025 405 66 1 0 AS,OO,DL
Apr 2025 401 52 1 0 DL,OO,AS
Mar 2025 410 62 0 1 AS,DL,OO
Feb 2025 369 68 5 0 AS,OO,DL
Jan 2025 401 49 4 0 AS,OO,DL
Dec 2024 375 61 1 1 AS,DL,OO
Nov 2024 405 27 1 0 OO,AS,DL
Oct 2024 439 40 3 2 AS,OO,DL
Sep 2024 472 62 0 0 OO,AS,DL
Aug 2024 459 70 2 2 AS,DL,OO
Jul 2024 438 65 4 0 AS,DL,OO
Jun 2024 423 86 0 0 AS,DL,OO
May 2024 467 66 1 0 AS,DL,OO
Apr 2024 452 50 1 0 AS,DL,OO
Mar 2024 430 38 2 0 AS,DL,OO
Feb 2024 443 34 2 0 AS,DL,OO
Jan 2024 477 113 48 0 AS,DL,OO

PDX–SEA seasonal on-time pattern

Best: October (91.1%) · weakest: December (82.8%)

82%84%86%88%90%92% JanFebMarAprMayJunJulAugSepOctNovDec 82.8%

Strongest calendar month

October

91.1% on-time · ~538 flights/mo

Busiest calendar month

September

~558 flights/mo avg

Weakest calendar month

December

82.8% on-time · ~475 flights/mo

Cancellation Rate

1.0%

98 of 10,310 flights

Diversion Rate

0.1%

6 of 10,310 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

PDX - Portland

Full on-time, delay-cause, and seasonal performance for Portland, OR.

PDX on-time profile

SEA - Seattle

Full on-time, delay-cause, and seasonal performance for Seattle, WA.

SEA on-time profile

Compare the two airports

See PDX and SEA side by side on delays, cancellations, and reliability.

Compare PDX vs SEA

Origin-hub reliability standing

Among PDX's stronger departures

PDX → SEA posts a 87.7% on-time rate, landing in the ≥85% band with 26 of 44 BTS-tracked routes leaving Portland. The same hub also shows 17 mid-band and 1 challenged departures · fleet-wide on-time rank #486 of 4927 (highest on-time = #1).

What the Data Says About PDX to SEA

Portland to Seattle (PDX to SEA) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 87.7% on-time rate across 36,148 flights, with delays that do happen averaging 65.3 minutes. The corridor runs roughly 129 miles and is served by 19 carriers. Over the most recent 24 months, 98 of 10,310 flights were cancelled (1.0%) and 6 diverted (0.1%).

The monthly split is wide on this route: Nov 2024 posted the strongest performance at 93% on-time, while Jun 2025 came in at just 75% - a 18-point swing worth factoring into travel timing.

On the multi-year calendar, PDX–SEA peaks in October at 91.1% on-time while September carries the heaviest traffic (~558 flights per month) ; the softest month is December at 82.8%, a 8.3-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does PDX to SEA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, PDX to SEA ranks #57 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from PDX to SEA? ▼
Flights from Portland to Seattle have a 87.7% on-time rate based on 36,148 flights. The average delay is 65.3 minutes. The best recent month was Nov 2024 with 93% on-time.
What is the cancellation rate for PDX to SEA? ▼
Over the last 24 months, 1.0% of flights on this route were cancelled (98 of 10,310 flights) and 0.1% were diverted.
How far is the flight from PDX to SEA? ▼
The flight distance from Portland (PDX) to Seattle (SEA) is approximately 129 miles. This route is served by 19 carriers.
When is the best time to fly from PDX to SEA? ▼
The best recent month for on-time performance was Nov 2024 (93% on-time). The worst was Jun 2025 (75% on-time). Consider booking during months with historically better performance.

Airports on this route

PDX Airport

Portland
SEA Airport

Seattle
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using PDX–SEA data

PDX–SEA runs 8.7 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare PDX and SEA airport profiles: delay causes and top routes differ even on the same corridor. PDX airport
  • If your dates flex, October (91.1% on-time) beats December (82.8%) on this corridor. Seasonal chart
  • 4 other routes post a similar 87.7% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.