Best time to fly Philadelphia to Buffalo

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

Best month

April

82.8% on time · 30 flights

Worst month

December

52.9% on time · 21 flights

Month Flights On time Cancelled When late, by
February 17 60% 11.76% 188 min
March 31 72.4% 6.45% 74 min
April 30 82.8% 3.33% 50 min
May 29 71.4% 3.45% 81 min
June 42 61% 2.38% 91 min
July 153 65.2% 9.15% 108 min
August 104 64.3% 5.77% 58 min
September 65 76.9% 0% 33 min
October 93 80.4% 1.08% 46 min
November 34 65.6% 5.88% 170 min
December 21 52.9% 19.05% 74 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.