Best time to fly Sioux Falls to Denver

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

Best month

February

90.8% on time · 121 flights

Worst month

July

64.4% on time · 197 flights

Month Flights On time Cancelled When late, by
January 130 86.8% 0.77% 104 min
February 121 90.8% 0.83% 79 min
March 134 79.5% 5.22% 76 min
April 133 83.3% 0.75% 118 min
May 169 79.3% 0% 81 min
June 180 79.4% 0% 99 min
July 197 64.4% 2.03% 98 min
August 185 70.2% 1.08% 116 min
September 159 81% 0.63% 63 min
October 161 85% 0% 36 min
November 131 83.6% 2.29% 85 min
December 132 65.4% 3.79% 104 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.