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Route · SAN → SEA · 2020–2025 BTS data

San Diego to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SAN to SEA (San Diego to Seattle) ranks #205 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

85.2%
On-time
+6.2 pts
vs US avg
70 min
Delay when late
25,268
Flights
#205 of 4927
Corpus placement

Cancelled

1.5%

Best Month

Feb 2024 86%

Worst Month

Aug 2025 70%

Distance

1,050 mi

Carriers

13

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 355 79 10 0 DL,AS
Nov 2025 320 66 5 1 OO,DL,AS
Oct 2025 348 60 8 0 AS,DL
Sep 2025 388 57 5 0 DL,AS
Aug 2025 426 128 9 0 AS,DL
Jul 2025 446 108 11 0 AS,DL
Jun 2025 427 116 6 1 AS,DL
May 2025 416 85 1 0 AS,DL
Apr 2025 366 56 2 0 DL,AS
Mar 2025 354 69 4 2 AS,DL
Feb 2025 306 60 4 0 AS,DL
Jan 2025 346 55 2 0 AS,OO,DL
Dec 2024 391 92 6 0 AS,DL,OO
Nov 2024 353 62 0 2 OO,AS,DL
Oct 2024 386 89 2 0 AS,OO,DL
Sep 2024 423 87 2 0 OO,AS,DL
Aug 2024 437 91 3 0 AS,DL,OO
Jul 2024 438 89 8 0 AS,DL
Jun 2024 410 97 1 1 AS,DL,OO
May 2024 396 63 1 0 AS,DL,OO
Apr 2024 367 58 1 0 AS,DL,OO
Mar 2024 376 69 3 0 AS,DL,OO
Feb 2024 337 46 3 0 AS,DL,OO
Jan 2024 351 66 38 0 AS,DL,OO

SAN–SEA seasonal on-time pattern

Best: April (87.2%) · weakest: June (82.2%)

80%82%84%86%88% JanFebMarAprMayJunJulAugSepOctNovDec 82.9%

Strongest calendar month

April

87.2% on-time · ~331 flights/mo

Busiest calendar month

August

~389 flights/mo avg

Weakest calendar month

June

82.2% on-time · ~361 flights/mo

Cancellation Rate

1.5%

135 of 9,163 flights

Diversion Rate

0.1%

7 of 9,163 flights

Explore origin & destination

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

SAN - San Diego

Full on-time, delay-cause, and seasonal performance for San Diego, CA.

SAN 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 SAN and SEA side by side on delays, cancellations, and reliability.

Compare SAN vs SEA

Origin-hub reliability standing

Among SAN's stronger departures

SAN → SEA posts a 85.2% on-time rate, landing in the ≥85% band with 13 of 51 BTS-tracked routes leaving San Diego. The same hub also shows 34 mid-band and 4 challenged departures · fleet-wide on-time rank #1162 of 4927 (highest on-time = #1).

What the Data Says About SAN to SEA

San Diego to Seattle (SAN to SEA) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 85.2% on-time rate across 25,268 flights, with delays that do happen averaging 69.8 minutes. The corridor runs roughly 1,050 miles and is served by 13 carriers. Over the most recent 24 months, 135 of 9,163 flights were cancelled (1.5%) and 7 diverted (0.1%).

The monthly split is wide on this route: Feb 2024 posted the strongest performance at 86% on-time, while Aug 2025 came in at just 70% - a 16-point swing worth factoring into travel timing.

On the multi-year calendar, SAN–SEA peaks in April at 87.2% on-time while August carries the heaviest traffic (~389 flights per month) ; the softest month is June at 82.2%, a 5.0-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SAN to SEA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SAN to SEA ranks #205 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 SAN to SEA? ▼
Flights from San Diego to Seattle have a 85.2% on-time rate based on 25,268 flights. The average delay is 69.8 minutes. The best recent month was Feb 2024 with 86% on-time.
What is the cancellation rate for SAN to SEA? ▼
Over the last 24 months, 1.5% of flights on this route were cancelled (135 of 9,163 flights) and 0.1% were diverted.
How far is the flight from SAN to SEA? ▼
The flight distance from San Diego (SAN) to Seattle (SEA) is approximately 1,050 miles. This route is served by 13 carriers.
When is the best time to fly from SAN to SEA? ▼
The best recent month for on-time performance was Feb 2024 (86% on-time). The worst was Aug 2025 (70% on-time). Consider booking during months with historically better performance.

Airports on this route

SAN Airport

San Diego
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 SAN–SEA data

SAN–SEA runs 6.2 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SAN and SEA airport profiles: delay causes and top routes differ even on the same corridor. SAN airport
  • If your dates flex, April (87.2% on-time) beats June (82.2%) on this corridor. Seasonal chart
  • 4 other routes post a similar 85.2% 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.