Best time to fly Buffalo to Boston

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

Best month

May

89.7% on time · 167 flights

Worst month

January

55.3% on time · 51 flights

Month Flights On time Cancelled When late, by
January 51 55.3% 7.84% 88 min
February 38 68.6% 7.89% 43 min
March 109 76.1% 0% 100 min
April 104 76% 0% 59 min
May 167 89.7% 1.2% 77 min
June 169 81.6% 3.55% 68 min
July 123 62.3% 0.81% 79 min
August 124 83.7% 0.81% 53 min
September 88 71.3% 1.14% 73 min
October 105 68% 1.9% 61 min
November 85 78.8% 0% 105 min
December 72 59.1% 8.33% 64 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.