Best time to fly Cheyenne to Denver

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

Best month

September

95% on time · 60 flights

Worst month

July

64.3% on time · 72 flights

Month Flights On time Cancelled When late, by
January 62 85.2% 1.61% 84 min
February 56 81.5% 3.57% 81 min
March 62 81.4% 4.84% 125 min
April 60 81.7% 0% 123 min
May 62 85% 1.61% 92 min
June 60 83.3% 0% 90 min
July 72 64.3% 2.78% 86 min
August 62 80% 1.61% 127 min
September 60 95% 0% 79 min
October 62 79% 0% 55 min
November 59 94.9% 0% 84 min
December 63 79.4% 0% 76 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.