Best time to fly Phoenix to Denver

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

Best month

April

85.7% on time · 826 flights

Worst month

July

64.1% on time · 658 flights

Month Flights On time Cancelled When late, by
January 731 83% 0.96% 60 min
February 722 82.6% 0.28% 66 min
March 922 74.6% 0.54% 70 min
April 826 85.7% 0% 57 min
May 768 76.5% 0.39% 60 min
June 676 69.4% 0% 65 min
July 658 64.1% 1.67% 71 min
August 613 71.9% 0.82% 66 min
September 662 78% 0.6% 77 min
October 802 79.5% 0.12% 55 min
November 769 79.2% 2.34% 73 min
December 771 78.3% 0.78% 57 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.