Best time to fly Milwaukee to Boston

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

Best month

March

97.8% on time · 48 flights

Worst month

September

46.8% on time · 78 flights

Month Flights On time Cancelled When late, by
January 31 67.9% 9.68% 48 min
February 28 84.6% 7.14% 105 min
March 48 97.8% 4.17% 173 min
April 51 76.5% 0% 41 min
May 83 77.1% 0% 63 min
June 82 85% 2.44% 66 min
July 85 51.9% 3.53% 82 min
August 87 76.7% 1.15% 69 min
September 78 46.8% 1.28% 54 min
October 82 48.8% 2.44% 73 min
November 54 80.9% 12.96% 47 min
December 32 71% 3.13% 69 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.