Best time to fly Raleigh/Durham to New York

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

Best month

April

84% on time · 156 flights

Worst month

July

67.2% on time · 217 flights

Month Flights On time Cancelled When late, by
January 184 78% 10.33% 70 min
February 185 75.5% 11.89% 60 min
March 197 75.9% 1.52% 76 min
April 156 84% 0% 63 min
May 163 83.3% 0.61% 38 min
June 187 68.3% 2.14% 96 min
July 217 67.2% 12.9% 86 min
August 201 77.5% 0.5% 63 min
September 197 81.5% 1.02% 86 min
October 195 73.4% 1.54% 78 min
November 247 76.7% 4.45% 72 min
December 233 68.8% 3.86% 62 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.