Best time to fly Phoenix to Chicago

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

Best month

February

84.7% on time · 445 flights

Worst month

June

68.2% on time · 414 flights

Month Flights On time Cancelled When late, by
January 447 77.9% 1.34% 78 min
February 445 84.7% 0% 42 min
March 586 72.8% 2.56% 100 min
April 537 74.9% 2.23% 84 min
May 499 76.6% 0.2% 53 min
June 414 68.2% 2.17% 99 min
July 439 72.6% 2.51% 71 min
August 416 78.2% 1.92% 82 min
September 436 79.3% 1.15% 79 min
October 440 78.7% 0.45% 57 min
November 444 72.9% 4.5% 84 min
December 490 79.8% 0.41% 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.