SEA (Seattle) to DEN (Denver) flights arrive on time 78% of the time. The most reliable airline on this route is United Airlines at 88%. The average delay is 61 minutes. Delays on this route are most often caused by the incoming plane arriving late.
Source: Bureau of Transportation Statistics. Updated April 2026.SEA → DEN
SEA (Seattle) to DEN (Denver)
SEA → DEN on-time performance by month
24
25
JanFebMarAprMayJunJulAugSepOctNovDec
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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?
United Airlines is significantly more reliable on this route at 88% on time vs Frontier Airlines at 71%.
Airline Comparison
United Airlines leads at 88% on time; Frontier Airlines trails at 71%.
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 ~22 min. Best time: 4 AM (about 5 min).
Arriving at DEN
78% on timeWhen flights into DEN are late, the average delay is 67 minutes. Build buffer if you have ground plans.
If connecting at DEN: TSA is ~30 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.