Best time to fly Washington to New York

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

There is not yet enough of the year on record for this route to say anything about seasons. The months below are shown as recorded.

Month Flights On time Cancelled When late, by
March 47 67.4% 2.13% 60 min
April 60 74.6% 1.67% 58 min
May 37 58.3% 2.7% 99 min
June 30 40% 0% 53 min
July 62 59% 1.61% 99 min
August 62 56.4% 11.29% 91 min
September 60 81.7% 0% 54 min
October 62 91.9% 0% 56 min
November 60 70% 0% 45 min
December 51 62% 1.96% 125 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.