Best time to fly Denver to Bismarck/Mandan

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

Best month

November

92% on time · 116 flights

Worst month

August

64.9% on time · 152 flights

Month Flights On time Cancelled When late, by
January 119 72% 0.84% 83 min
February 106 78.3% 0% 162 min
March 120 80.2% 3.33% 108 min
April 119 77.3% 0% 48 min
May 121 81.8% 0% 63 min
June 116 76.7% 0% 99 min
July 154 68% 1.3% 69 min
August 152 64.9% 0.66% 101 min
September 137 78.8% 0% 56 min
October 120 81.5% 0% 41 min
November 116 92% 2.59% 153 min
December 122 69.2% 0% 115 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.