Best time to fly Charleston to Seattle

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

There is not yet enough of the year on record for this route to say anything about seasons. The months below are shown as recorded.

Month Flights On time Cancelled When late, by
January 24 62.5% 0% 22 min
February 25 84% 0% 32 min
March 31 74.2% 0% 31 min
April 30 76.7% 0% 27 min
May 31 80% 3.23% 47 min
June 30 83.3% 0% 38 min
July 31 46.7% 3.23% 51 min
August 31 71% 0% 36 min
September 30 83.3% 0% 71 min
October 30 69% 3.33% 53 min
November 23 69.6% 0% 31 min
December 31 54.8% 0% 33 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.