Best time to fly Seattle to Great Falls

Every month pooled across the years on record, so "July" means July generally rather than one particular July. Full SEA to GTF 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 51 80.4% 0% 37 min
February 51 76.5% 0% 51 min
March 44 88.4% 2.27% 68 min
April 21 85.7% 0% 57 min
May 17 76.5% 0% 29 min
June 11 81.8% 0% 66 min
August 12 91.7% 0% 47 min
September 30 83.3% 0% 56 min
October 3 66.7% 0% 15 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.