Best time to fly Seattle to Spokane

Every month pooled across the years on record, so "July" means July generally rather than one particular July. Full SEA to GEG record →

Best month

October

89% on time · 451 flights

Worst month

July

69.9% on time · 544 flights

Month Flights On time Cancelled When late, by
January 440 82.5% 2.27% 52 min
February 400 88.4% 0.25% 60 min
March 418 84.6% 2.15% 54 min
April 386 86% 0% 47 min
May 414 88.1% 0.24% 68 min
June 375 83.1% 0.27% 44 min
July 544 69.9% 0.92% 45 min
August 513 74.3% 0.58% 43 min
September 462 83.3% 0.22% 47 min
October 451 89% 0.89% 57 min
November 423 88% 3.31% 52 min
December 395 77.7% 0.76% 66 min

What a seasonal pattern can and cannot tell you

Months differ for reasons that repeat — summer thunderstorms in the American interior, winter fog and de-icing in northern Europe, school holidays filling every seat and leaving no slack in the schedule. Those are real and they come back each year.

What the pattern cannot do is forecast a particular flight. A quiet month has late days and a bad month has punctual ones. Treat this as a way to choose between two dates you are indifferent about, not as a promise.