SEA (Seattle) to DCA (Washington) flights arrive on time 81% of the time. The most reliable airline on this route is Delta Air Lines at 92%. The average delay is 57 minutes. Delays on this route are most often caused by air traffic and busy airspace.
Source: Bureau of Transportation Statistics. Updated August 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 81% of flights arrive on schedule.
Delays on this route are most often caused by air traffic and busy airspace.
Accurate?
Delta Air Lines is significantly more reliable on this route at 92% on time vs Alaska Airlines at 77%.
Airline Comparison
Delta Air Lines leads at 92% on time; Alaska Airlines trails at 77%.
Accurate?
Good to know
Departing from SEA
80% on timeExpect ~21 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
75% on timeWhen flights into DCA are late, the average delay is 79 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 3.2% 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.
Flying out of SEA? We'll brief you.
Delays, TSA, weather, gates — we'll let you know if something matters.
Know someone flying soon?
Send them the link — delay data, TSA waits, weather, all free.
Data last updated August 2026. Source: Bureau of Transportation Statistics.