Best time to fly Boston to Buffalo

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

Best month

May

86.7% on time · 167 flights

Worst month

December

53% on time · 72 flights

Month Flights On time Cancelled When late, by
January 50 57.8% 10% 86 min
February 38 68.6% 7.89% 89 min
March 110 68.8% 0.91% 73 min
April 105 78.1% 0% 55 min
May 167 86.7% 1.2% 56 min
June 169 79.3% 2.96% 68 min
July 123 69.7% 0.81% 89 min
August 124 86.2% 0.81% 50 min
September 87 70.9% 1.15% 70 min
October 106 76.9% 1.89% 75 min
November 84 78.6% 0% 73 min
December 72 53% 8.33% 65 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.