Best time to fly Denver to Idaho Falls

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

Best month

September

88.3% on time · 284 flights

Worst month

June

69% on time · 314 flights

Month Flights On time Cancelled When late, by
January 253 76.1% 0.79% 82 min
February 223 77.2% 0.9% 68 min
March 248 81.7% 2.02% 82 min
April 239 78.9% 0.42% 80 min
May 291 78.4% 1.03% 75 min
June 314 69% 0.32% 74 min
July 299 72% 1% 66 min
August 301 76.4% 1.33% 64 min
September 284 88.3% 0% 70 min
October 270 86.2% 0% 78 min
November 257 87.8% 1.17% 54 min
December 263 83.1% 0% 95 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.