Best time to fly Raleigh/Durham to Phoenix

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

Best month

September

100% on time · 51 flights

Worst month

June

45.7% on time · 81 flights

Month Flights On time Cancelled When late, by
January 46 87.8% 10.87% 39 min
February 59 82.5% 3.39% 31 min
March 89 88.8% 0% 57 min
April 84 86.9% 0% 40 min
May 87 89.7% 0% 51 min
June 81 45.7% 0% 67 min
July 62 90.2% 0% 102 min
August 53 92.3% 1.89% 200 min
September 51 100% 0%
October 60 93.3% 0% 16 min
November 70 84.1% 0% 67 min
December 69 79.7% 0% 46 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.