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Route · SEA → PDX · 2020–2025 BTS data

Seattle to Portland

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to PDX (Seattle to Portland) ranks #64 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

83.7%
On-time
+4.7 pts
vs US avg
55 min
Delay when late
35,578
Flights
#64 of 4927
Corpus placement

Cancelled

0.8%

Best Month

Oct 2025 88%

Worst Month

Jun 2024 67%

Distance

129 mi

Carriers

19

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 378 99 2 0 DL,AS,OO
Nov 2025 403 56 15 0 OO,DL,AS
Oct 2025 428 51 3 0 AS,OO,DL
Sep 2025 433 69 0 0 OO,DL,AS
Aug 2025 416 76 0 0 OO,AS,DL
Jul 2025 392 94 1 0 AS,OO,DL
Jun 2025 373 104 1 0 AS,DL,OO
May 2025 387 71 1 0 AS,DL,OO
Apr 2025 402 59 0 0 DL,OO,AS
Mar 2025 410 63 0 0 AS,OO,DL
Feb 2025 369 102 8 0 AS,OO,DL
Jan 2025 400 67 3 0 AS,OO,DL
Dec 2024 373 70 1 0 AS,DL,OO
Nov 2024 400 58 1 0 OO,AS,DL
Oct 2024 440 58 1 1 AS,OO,DL
Sep 2024 473 98 0 0 OO,AS,DL
Aug 2024 460 117 0 0 AS,DL,OO
Jul 2024 437 124 2 0 AS,DL,OO
Jun 2024 422 139 0 0 AS,DL,OO
May 2024 464 114 0 0 AS,DL,OO
Apr 2024 446 80 0 0 AS,DL,OO
Mar 2024 421 78 0 0 AS,DL,OO
Feb 2024 445 62 0 0 AS,DL,OO
Jan 2024 478 123 40 1 AS,DL,OO

SEA–PDX seasonal on-time pattern

Best: October (88.6%) · weakest: December (75.8%)

75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 75.8%

Strongest calendar month

October

88.6% on-time · ~527 flights/mo

Busiest calendar month

September

~548 flights/mo avg

Weakest calendar month

December

75.8% on-time · ~466 flights/mo

Cancellation Rate

0.8%

79 of 10,050 flights

Diversion Rate

0.0%

2 of 10,050 flights

Explore origin & destination

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

SEA - Seattle

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

SEA on-time profile

PDX - Portland

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

PDX on-time profile

Compare the two airports

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

Compare SEA vs PDX

Origin-hub reliability standing

Mid-pack among SEA departures

From SEA, this corridor sits with 63 other 75–85% on-time routes out of 89 tracked departures, not the hub's reliability leaders (25 at ≥85%) and not the softest ( 1 below 75%). Destination: Portland · fleet on-time rank #1704 of 4927.

What the Data Says About SEA to PDX

Bureau of Transportation Statistics records show Seattle to Portland (SEA to PDX) running a 83.7% on-time rate over 35,578 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 55.3 minutes. The 129-mile corridor is served by 19 carriers, and over the last 24 months 0.8% of 10,050 flights were cancelled, 0.0% diverted.

The monthly split is wide on this route: Oct 2025 posted the strongest performance at 88% on-time, while Jun 2024 came in at just 67% - a 21-point swing worth factoring into travel timing.

On the multi-year calendar, SEA–PDX peaks in October at 88.6% on-time while September carries the heaviest traffic (~548 flights per month) ; the softest month is December at 75.8%, a 12.8-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SEA to PDX rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SEA to PDX ranks #64 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 SEA to PDX? ▼
Flights from Seattle to Portland have a 83.7% on-time rate based on 35,578 flights. The average delay is 55.3 minutes. The best recent month was Oct 2025 with 88% on-time.
What is the cancellation rate for SEA to PDX? ▼
Over the last 24 months, 0.8% of flights on this route were cancelled (79 of 10,050 flights) and 0.0% were diverted.
How far is the flight from SEA to PDX? ▼
The flight distance from Seattle (SEA) to Portland (PDX) is approximately 129 miles. This route is served by 19 carriers.
When is the best time to fly from SEA to PDX? ▼
The best recent month for on-time performance was Oct 2025 (88% on-time). The worst was Jun 2024 (67% on-time). Consider booking during months with historically better performance.

Airports on this route

SEA Airport

Seattle
PDX Airport

Portland
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 SEA–PDX data

SEA–PDX runs 4.7 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SEA and PDX airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
  • If your dates flex, October (88.6% on-time) beats December (75.8%) on this corridor. Seasonal chart
  • 4 other routes post a similar 83.7% 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.