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Route · SFO → SEA · 2020–2025 BTS data

San Francisco to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SFO to SEA (San Francisco to Seattle) ranks #43 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

82.1%
On-time
+3.1 pts
vs US avg
63 min
Delay when late
37,671
Flights
#43 of 4927
Corpus placement

Cancelled

1.3%

Best Month

Jan 2025 88%

Worst Month

Jun 2025 66%

Distance

679 mi

Carriers

26

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 559 145 4 3 DL,AS,UA,OO
Nov 2025 565 114 12 0 OO,UA,DL,AS
Oct 2025 585 155 6 0 AS,OO,UA,DL
Sep 2025 585 128 3 1 UA,OO,DL,AS
Aug 2025 620 176 4 0 OO,UA,AS,DL
Jul 2025 639 207 13 0 AS,DL,OO,UA
Jun 2025 631 214 4 0 AS,DL,OO,UA
May 2025 636 179 2 0 AS,DL,OO,UA
Apr 2025 540 82 4 0 DL,OO,UA,AS
Mar 2025 553 119 2 2 AS,DL,OO,UA
Feb 2025 482 99 11 1 AS,DL,OO,UA
Jan 2025 526 65 0 0 AS,DL,OO,UA
Dec 2024 533 126 2 0 AS,DL,OO,UA
Nov 2024 547 100 9 0 OO,UA,AS,DL
Oct 2024 609 98 5 0 UA,AS,OO,DL
Sep 2024 617 154 5 0 OO,UA,AS,DL
Aug 2024 628 189 12 0 AS,DL,OO,UA
Jul 2024 624 173 15 0 AS,DL,OO,UA
Jun 2024 523 168 2 0 AS,DL,OO,UA
May 2024 547 165 4 0 AS,DL,OO,UA
Apr 2024 515 150 1 0 AS,DL,OO,UA
Mar 2024 521 155 3 1 AS,DL,OO,UA
Feb 2024 445 96 3 1 AS,DL,OO,UA
Jan 2024 489 83 51 0 AS,DL,OO,UA

SFO–SEA seasonal on-time pattern

Best: November (85.4%) · weakest: June (75.1%)

70%75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 77.5%

Strongest calendar month

November

85.4% on-time · ~519 flights/mo

Busiest calendar month

August

~570 flights/mo avg

Weakest calendar month

June

75.1% on-time · ~497 flights/mo

Cancellation Rate

1.3%

177 of 13,519 flights

Diversion Rate

0.1%

9 of 13,519 flights

Origin-hub reliability standing

Mid-pack among SFO departures

From SFO, this corridor sits with 50 other 75–85% on-time routes out of 73 tracked departures, not the hub's reliability leaders (20 at ≥85%) and not the softest ( 3 below 75%). Destination: Seattle · fleet on-time rank #2326 of 4927.

What the Data Says About SFO to SEA

Bureau of Transportation Statistics records show San Francisco to Seattle (SFO to SEA) running a 82.1% on-time rate over 37,671 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 62.8 minutes. The 679-mile corridor is served by 26 carriers, and over the last 24 months 1.3% of 13,519 flights were cancelled, 0.1% diverted.

The monthly split is wide on this route: Jan 2025 posted the strongest performance at 88% on-time, while Jun 2025 came in at just 66% - a 22-point swing worth factoring into travel timing.

On the multi-year calendar, SFO–SEA peaks in November at 85.4% on-time while August carries the heaviest traffic (~570 flights per month) ; the softest month is June at 75.1%, a 10.3-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SFO to SEA rank among US routes by traffic?
According to PlainFlights' route traffic ranking, SFO to SEA ranks #43 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 SFO to SEA?
Flights from San Francisco to Seattle have a 82.1% on-time rate based on 37,671 flights. The average delay is 62.8 minutes. The best recent month was Jan 2025 with 88% on-time.
What is the cancellation rate for SFO to SEA?
Over the last 24 months, 1.3% of flights on this route were cancelled (177 of 13,519 flights) and 0.1% were diverted.
How far is the flight from SFO to SEA?
The flight distance from San Francisco (SFO) to Seattle (SEA) is approximately 679 miles. This route is served by 26 carriers.
When is the best time to fly from SFO to SEA?
The best recent month for on-time performance was Jan 2025 (88% on-time). The worst was Jun 2025 (66% on-time). Consider booking during months with historically better performance.

Airports on this route

Data source

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

Using SFO–SEA data

SFO–SEA runs 3.1 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SFO and SEA airport profiles: delay causes and top routes differ even on the same corridor. SFO airport
  • If your dates flex, November (85.4% on-time) beats June (75.1%) on this corridor. Seasonal chart
  • 4 other routes post a similar 82.1% 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.