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Route · SEA → SAN · 2020–2025 BTS data

Seattle to San Diego

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to SAN (Seattle to San Diego) ranks #206 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

83%
On-time
+4 pts
vs US avg
54 min
Delay when late
25,263
Flights
#206 of 4927
Corpus placement

Cancelled

1.2%

Best Month

Jan 2025 84%

Worst Month

Dec 2025 69%

Distance

1,050 mi

Carriers

14

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 358 110 7 3 DL,AS
Nov 2025 319 91 0 3 DL,AS
Oct 2025 348 83 8 3 AS,DL
Sep 2025 387 69 6 4 DL,AS
Aug 2025 426 116 7 0 AS,DL
Jul 2025 446 104 12 1 AS,DL
Jun 2025 427 96 3 0 AS,DL
May 2025 412 94 1 0 AS,DL
Apr 2025 366 69 0 0 DL,AS
Mar 2025 354 67 2 1 AS,DL
Feb 2025 306 75 5 1 AS,DL
Jan 2025 345 55 2 1 AS,DL,OO
Dec 2024 390 90 6 6 AS,DL,OO
Nov 2024 353 68 0 0 OO,AS,DL
Oct 2024 387 97 1 2 AS,OO,DL
Sep 2024 422 78 2 0 OO,AS,DL
Aug 2024 436 106 1 0 AS,DL,OO
Jul 2024 438 96 5 1 AS,DL
Jun 2024 410 103 0 0 AS,DL,OO
May 2024 396 76 1 0 AS,DL,OO
Apr 2024 368 71 1 0 AS,DL,OO
Mar 2024 374 75 1 2 AS,DL,OO
Feb 2024 336 62 1 0 AS,DL,OO
Jan 2024 351 72 40 1 AS,DL,OO

SEA–SAN seasonal on-time pattern

Best: March (85.4%) · weakest: December (77.8%)

76%78%80%82%84%86% JanFebMarAprMayJunJulAugSepOctNovDec 77.8%

Strongest calendar month

March

85.4% on-time · ~356 flights/mo

Busiest calendar month

August

~389 flights/mo avg

Weakest calendar month

December

77.8% on-time · ~349 flights/mo

Cancellation Rate

1.2%

112 of 9,155 flights

Diversion Rate

0.3%

29 of 9,155 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

SAN - San Diego

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

SAN on-time profile

Compare the two airports

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

Compare SEA vs SAN

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: San Diego · fleet on-time rank #1962 of 4927.

What the Data Says About SEA to SAN

Bureau of Transportation Statistics records show Seattle to San Diego (SEA to SAN) running a 83% on-time rate over 25,263 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 53.9 minutes. The 1,050-mile corridor is served by 14 carriers, and over the last 24 months 1.2% of 9,155 flights were cancelled, 0.3% diverted.

Monthly performance varies moderately here: Jan 2025 was the strongest month at 84% on-time versus Dec 2025 at 69%, a 15-point difference.

On the multi-year calendar, SEA–SAN peaks in March at 85.4% on-time while August carries the heaviest traffic (~389 flights per month) ; the softest month is December at 77.8%, a 7.6-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SEA to SAN rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SEA to SAN ranks #206 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 SAN? ▼
Flights from Seattle to San Diego have a 83% on-time rate based on 25,263 flights. The average delay is 53.9 minutes. The best recent month was Jan 2025 with 84% on-time.
What is the cancellation rate for SEA to SAN? ▼
Over the last 24 months, 1.2% of flights on this route were cancelled (112 of 9,155 flights) and 0.3% were diverted.
How far is the flight from SEA to SAN? ▼
The flight distance from Seattle (SEA) to San Diego (SAN) is approximately 1,050 miles. This route is served by 14 carriers.
When is the best time to fly from SEA to SAN? ▼
The best recent month for on-time performance was Jan 2025 (84% on-time). The worst was Dec 2025 (69% on-time). Consider booking during months with historically better performance.

Airports on this route

SEA Airport

Seattle
SAN Airport

San Diego
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–SAN data

SEA–SAN runs 4 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 SAN airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
  • If your dates flex, March (85.4% on-time) beats December (77.8%) on this corridor. Seasonal chart
  • 4 other routes post a similar 83% 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.