Best time to fly New York to Philadelphia

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

Best month

September

88.2% on time · 170 flights

Worst month

June

50% on time · 4 flights

Month Flights On time Cancelled When late, by
January 58 79.3% 0% 37 min
February 56 67.9% 5.36% 46 min
March 62 77.4% 0% 60 min
April 60 76.7% 0% 53 min
May 31 87.1% 0% 48 min
June 4 50% 0% 44 min
July 173 79.8% 2.89% 54 min
August 172 85.6% 11.05% 68 min
September 170 88.2% 0% 40 min
October 175 87.9% 0% 56 min
November 66 78.8% 0% 30 min
December 49 72.3% 2.04% 58 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.