BWI (Baltimore) to SEA (Seattle) flights arrive on time 69% of the time. The most reliable airline on this route is Southwest Airlines at 74%. The average delay is 55 minutes. Delays on this route are most often caused by the incoming plane arriving late.
Source: Bureau of Transportation Statistics. Updated August 2026.BWI → SEA
BWI (Baltimore) to SEA (Seattle)
BWI → SEA on-time performance by month
24
25
26
JanFebMarAprMayJunJulAugSepOctNovDec
Worse
Better
This route is delayed fairly often. About 69% of flights arrive on schedule.
Delays on this route are most often caused by the incoming plane arriving late.
Accurate?
Southwest Airlines edges out Alaska Airlines on this route — 74% vs 68% on time.
Airline Comparison
Southwest Airlines leads at 74% on time; Alaska Airlines trails at 68%.
Accurate?
Good to know
Departing from BWI
80% on timeTSA is currently ~5 min. Best time: 4 AM (about 5 min).
Arriving at SEA
80% on timeWhen flights into SEA are late, the average delay is 57 minutes. Build buffer if you have ground plans.
If connecting at SEA: TSA is ~5 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what Southwest Airlines owes you — refund rights, action plan, complaint email. Free.
Flying out of BWI? 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.