Best time to fly Chicago to New York

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

Best month

October

83.4% on time · 461 flights

Worst month

July

65.1% on time · 400 flights

Month Flights On time Cancelled When late, by
January 322 71.7% 3.42% 77 min
February 286 74% 5.59% 79 min
March 316 68.6% 2.85% 96 min
April 269 80.1% 1.12% 71 min
May 336 80.7% 0.6% 77 min
June 356 73.8% 4.21% 119 min
July 400 65.1% 4.75% 115 min
August 398 66% 5.03% 84 min
September 434 79.7% 0% 68 min
October 461 83.4% 0.65% 85 min
November 388 79.8% 1.8% 84 min
December 394 66.7% 1.78% 77 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.