PlainFlights

Route · DCA → SEA · 2020–2025 BTS data

Washington to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), DCA to SEA (Washington to Seattle) ranks #2719 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

82.3%
On-time
+3.3 pts
vs US avg
74 min
Delay when late
4,426
Flights
#2719 of 4927
Corpus placement

Cancelled

1.2%

Best Month

Sep 2024 92%

Worst Month

Dec 2025 46%

Distance

2,329 mi

Carriers

3

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 93 50 2 0 DL,AS
Nov 2025 89 24 0 0 AS,DL
Oct 2025 93 18 0 0 AS,DL
Sep 2025 90 15 0 0 DL,AS
Aug 2025 93 13 2 0 AS,DL
Jul 2025 93 36 4 1 AS,DL
Jun 2025 90 22 0 0 AS,DL
May 2025 93 15 0 0 AS,DL
Apr 2025 90 9 0 0 DL,AS
Mar 2025 85 12 1 1 AS,DL
Feb 2025 56 21 4 0 AS
Jan 2025 62 16 4 0 AS
Dec 2024 62 14 0 0 AS
Nov 2024 59 5 1 0 AS
Oct 2024 62 6 0 0 AS
Sep 2024 60 5 0 0 AS
Aug 2024 62 9 0 0 AS
Jul 2024 62 12 0 0 AS
Jun 2024 60 9 1 1 AS
May 2024 62 11 0 0 AS
Apr 2024 60 9 0 0 AS
Mar 2024 62 7 0 0 AS
Feb 2024 58 6 0 0 AS
Jan 2024 62 16 2 0 AS

DCA–SEA seasonal on-time pattern

Best: October (90.7%) · weakest: December (72.3%)

70%75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 72.3%

Strongest calendar month

October

90.7% on-time · ~63 flights/mo

Busiest calendar month

August

~67 flights/mo avg

Weakest calendar month

December

72.3% on-time · ~62 flights/mo

Cancellation Rate

1.2%

21 of 1,758 flights

Diversion Rate

0.2%

3 of 1,758 flights

Explore origin & destination

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

DCA - Washington

Full on-time, delay-cause, and seasonal performance for Washington, DC.

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

Compare DCA vs SEA

Origin-hub reliability standing

Mid-pack among DCA departures

From DCA, this corridor sits with 77 other 75–85% on-time routes out of 91 tracked departures, not the hub's reliability leaders (4 at ≥85%) and not the softest ( 10 below 75%). Destination: Seattle · fleet on-time rank #2226 of 4927.

What the Data Says About DCA to SEA

Bureau of Transportation Statistics records show Washington to Seattle (DCA to SEA) running a 82.3% on-time rate over 4,426 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 73.7 minutes. The 2,329-mile corridor is served by 3 carriers, and over the last 24 months 1.2% of 1,758 flights were cancelled, 0.2% diverted.

The monthly split is wide on this route: Sep 2024 posted the strongest performance at 92% on-time, while Dec 2025 came in at just 46% - a 45-point swing worth factoring into travel timing.

On the multi-year calendar, DCA–SEA peaks in October at 90.7% on-time while August carries the heaviest traffic (~67 flights per month) ; the softest month is December at 72.3%, a 18.4-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does DCA to SEA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, DCA to SEA ranks #2719 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 DCA to SEA? ▼
Flights from Washington to Seattle have a 82.3% on-time rate based on 4,426 flights. The average delay is 73.7 minutes. The best recent month was Sep 2024 with 92% on-time.
What is the cancellation rate for DCA to SEA? ▼
Over the last 24 months, 1.2% of flights on this route were cancelled (21 of 1,758 flights) and 0.2% were diverted.
How far is the flight from DCA to SEA? ▼
The flight distance from Washington (DCA) to Seattle (SEA) is approximately 2,329 miles. This route is served by 3 carriers.
When is the best time to fly from DCA to SEA? ▼
The best recent month for on-time performance was Sep 2024 (92% on-time). The worst was Dec 2025 (46% on-time). Consider booking during months with historically better performance.

Airports on this route

DCA Airport

Washington
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 DCA–SEA data

DCA–SEA runs 3.3 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare DCA and SEA airport profiles: delay causes and top routes differ even on the same corridor. DCA airport
  • If your dates flex, October (90.7% on-time) beats December (72.3%) on this corridor. Seasonal chart
  • 4 other routes post a similar 82.3% 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.