Best time to fly Indianapolis to Boston

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

Best month

April

87.5% on time · 168 flights

Worst month

September

60.9% on time · 160 flights

Month Flights On time Cancelled When late, by
January 169 83.4% 7.1% 62 min
February 157 81.3% 8.28% 77 min
March 174 85.3% 2.3% 54 min
April 168 87.5% 0% 44 min
May 167 86.7% 0.6% 55 min
June 177 85.2% 0.56% 77 min
July 177 68.4% 3.39% 80 min
August 172 78.7% 1.74% 48 min
September 160 60.9% 2.5% 60 min
October 173 63.5% 1.73% 79 min
November 162 83.6% 1.85% 78 min
December 160 72.8% 1.25% 72 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.