BOS (Boston) to SEA (Seattle) flights arrive on time 78% of the time. The most reliable airline on this route is Delta Air Lines at 83%. The average delay is 62 minutes. Delays on this route are most often caused by the incoming plane arriving late.
Source: Bureau of Transportation Statistics. Updated April 2026.BOS → SEA
BOS (Boston) to SEA (Seattle)
BOS → SEA on-time performance by month
24
25
JanFebMarAprMayJunJulAugSepOctNovDec
Worse
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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 the incoming plane arriving late.
Accurate?
Delta Air Lines edges out JetBlue Airways on this route — 83% vs 76% on time.
Airline Comparison
Delta Air Lines leads at 83% on time; JetBlue Airways trails at 76%.
Accurate?
Good to know
Departing from BOS
79% on timeExpect ~19 min sitting on the taxiway after your gate pushes back. BOS has long runway queues.
TSA is currently ~20 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 ~15 min right now. Allow at least 60 minutes for a domestic connection.
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Data last updated April 2026. Source: Bureau of Transportation Statistics.