Best time to fly Chicago to Phoenix

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

Best month

February

80.9% on time · 446 flights

Worst month

June

62.3% on time · 416 flights

Month Flights On time Cancelled When late, by
January 446 75.1% 1.79% 70 min
February 446 80.9% 0% 54 min
March 585 77.7% 2.91% 83 min
April 537 66.9% 2.42% 75 min
May 499 75.7% 0.4% 80 min
June 416 62.3% 1.92% 103 min
July 441 63.6% 2.27% 69 min
August 416 73.2% 2.64% 81 min
September 435 75.7% 1.15% 87 min
October 439 75% 0.23% 53 min
November 445 75.1% 4.27% 85 min
December 489 72.3% 0.41% 71 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.