Best time to fly Denver to Phoenix

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

Best month

December

82.4% on time · 1,588 flights

Worst month

June

63.7% on time · 1,330 flights

Month Flights On time Cancelled When late, by
January 1,536 80.4% 0.59% 57 min
February 1,485 80.6% 0.47% 69 min
March 1,884 78.8% 0.64% 58 min
April 1,665 78.9% 0.78% 53 min
May 1,486 72.2% 0.61% 65 min
June 1,330 63.7% 1.28% 66 min
July 1,390 67% 1.51% 71 min
August 1,330 74.7% 1.2% 69 min
September 1,414 81.1% 0.71% 63 min
October 1,628 80% 0.25% 62 min
November 1,565 77.4% 1.47% 70 min
December 1,588 82.4% 0.31% 63 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.