Best time to fly Cleveland to Boston

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

Best month

April

91.8% on time · 245 flights

Worst month

December

72.8% on time · 280 flights

Month Flights On time Cancelled When late, by
January 186 73.7% 3.76% 70 min
February 172 75.5% 5.23% 71 min
March 226 85.6% 1.77% 111 min
April 245 91.8% 0% 48 min
May 303 83.4% 0.33% 80 min
June 319 79.1% 0.31% 68 min
July 344 75.5% 1.45% 71 min
August 345 86.9% 2.32% 118 min
September 314 79.3% 1.59% 62 min
October 324 83.3% 0% 60 min
November 302 84.3% 0.66% 63 min
December 280 72.8% 2.86% 90 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.