Best time to fly Denver to Sun Valley/Hailey/Ketchum

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

Best month

November

94.9% on time · 60 flights

Worst month

June

68.3% on time · 120 flights

Month Flights On time Cancelled When late, by
January 124 80.2% 0.81% 123 min
February 112 79.1% 0.89% 111 min
March 122 86.7% 0% 62 min
April 65 87.5% 0% 51 min
May 80 84.8% 1.25% 60 min
June 120 68.3% 0% 79 min
July 124 76.4% 0% 85 min
August 124 73.9% 0% 68 min
September 114 91.2% 0% 61 min
October 86 88.1% 0% 45 min
November 60 94.9% 1.67% 60 min
December 100 81.6% 1% 72 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.