SEA (Seattle) to PHL (Philadelphia) flights arrive on time 73% of the time. The most reliable airline on this route is American Airlines at 76%. The average delay is 52 minutes. Delays on this route are most often caused by the incoming plane arriving late.
Source: Bureau of Transportation Statistics. Updated March 2026.SEA → PHL
SEA (Seattle) to PHL (Philadelphia)
SEA → PHL on-time performance by month
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JanFebMarAprMayJunJulAugSepOctNovDec
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This route is delayed fairly often. About 73% 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 — American Airlines leads slightly at 76% vs Alaska Airlines at 74%.
Airline Comparison
American Airlines leads at 76% on time; Alaska Airlines trails at 74%.
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 PHL
79% on timeWhen flights into PHL are late, the average delay is 79 minutes. Build buffer if you have ground plans.
If connecting at PHL: 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.