SEA (Seattle) to DCA (Washington) flights arrive on time 78% of the time. The most reliable airline on this route is Delta Air Lines at 90%. The average delay is 54 minutes. Delays on this route are most often caused by air traffic and busy airspace.
Source: Bureau of Transportation Statistics. Updated March 2026.SEA → DCA
SEA (Seattle) to DCA (Washington)
SEA → DCA on-time performance by month
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This route is on time most of the time. About 78% of flights arrive on schedule.
Delays on this route are most often caused by air traffic and busy airspace.
Accurate?
Delta Air Lines edges out Alaska Airlines on this route — 90% vs 76% on time.
Airline Comparison
Delta Air Lines leads at 90% on time; Alaska Airlines trails at 76%.
Accurate?
Good to know
Departing from SEA
82% on timeExpect ~19 min sitting on the taxiway after your gate pushes back. SEA has long runway queues.
TSA is currently ~5 min. Best time: 4 AM (about 5 min).
Arriving at DCA
79% on timeWhen flights into DCA are late, the average delay is 74 minutes. Build buffer if you have ground plans.
If connecting at DCA: TSA is ~5 min right now. Allow at least 60 minutes for a domestic connection.
DCA has a 2.6% cancellation rate — keep the airline app handy for rebooking.
Flight cancelled or delayed?
Check what Delta Air Lines owes you — refund rights, action plan, complaint email. Free.
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Data last updated March 2026. Source: Bureau of Transportation Statistics.