Best time to fly Des Moines to Denver

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

Best month

October

89.1% on time · 385 flights

Worst month

July

76.8% on time · 436 flights

Month Flights On time Cancelled When late, by
January 319 84% 0.31% 86 min
February 294 82.1% 1.02% 56 min
March 363 88% 3.31% 102 min
April 348 85.6% 0.29% 93 min
May 407 80.5% 0.49% 80 min
June 434 76.9% 0.46% 70 min
July 436 76.8% 0.69% 98 min
August 439 78.8% 0.46% 70 min
September 429 88.8% 0% 82 min
October 385 89.1% 0% 68 min
November 335 87.8% 1.79% 78 min
December 333 81.6% 0.6% 85 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.