Best time to fly San Francisco to Sun Valley/Hailey/Ketchum

Every month pooled across the years on record, so "July" means July generally rather than one particular July. Full SFO to SUN 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 86 87.1% 1.16% 65 min
February 73 84.7% 0% 67 min
March 77 94.7% 0% 99 min
April 8 75% 0% 29 min
May 17 76.5% 0% 40 min
June 46 78.3% 0% 39 min
July 65 80% 0% 74 min
August 65 92.2% 0% 37 min
September 23 100% 0%
October 19 89.5% 0% 60 min
December 64 73.8% 3.13% 105 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.