Best time to fly New York to Pittsburgh

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

Best month

May

84.8% on time · 149 flights

Worst month

July

63.5% on time · 155 flights

Month Flights On time Cancelled When late, by
January 118 72.9% 9.32% 69 min
February 115 78.8% 8.7% 56 min
March 128 74.2% 2.34% 89 min
April 121 82.6% 0% 71 min
May 149 84.8% 2.68% 80 min
June 150 67.8% 2% 78 min
July 155 63.5% 18.71% 87 min
August 155 82.1% 2.58% 61 min
September 178 82.1% 2.81% 86 min
October 183 77% 2.73% 81 min
November 176 75.4% 4.55% 71 min
December 136 65.2% 2.94% 72 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.