BWI (Baltimore) to SEA (Seattle) flights arrive on time 71% 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 March 2026.BWI → SEA
BWI (Baltimore) to SEA (Seattle)
BWI → SEA on-time performance by month
24
25
JanFebMarAprMayJunJulAugSepOctNovDec
Worse
Better
This route is delayed fairly often. About 71% of flights arrive on schedule.
Delays on this route are most often caused by the incoming plane arriving late.
Accurate?
Airlines are roughly equal on this route — Southwest Airlines leads slightly at 74% vs Alaska Airlines at 70%.
Airline Comparison
Southwest Airlines leads at 74% on time; Alaska Airlines trails at 70%.
Accurate?
Good to know
Departing from BWI
78% on timeTSA is currently ~5 min. Best time: 4 AM (about 5 min).
Arriving at SEA
82% 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.
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Data last updated March 2026. Source: Bureau of Transportation Statistics.