Best time to fly Boston to Nashville

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

Best month

November

80% on time · 452 flights

Worst month

June

66.2% on time · 550 flights

Month Flights On time Cancelled When late, by
January 335 76.8% 6.27% 55 min
February 307 76.3% 3.91% 55 min
March 467 78.3% 1.07% 68 min
April 488 75.9% 0% 50 min
May 561 68.6% 0.18% 75 min
June 550 66.2% 0.55% 65 min
July 559 67.9% 2.68% 70 min
August 527 79.2% 2.09% 68 min
September 531 78.4% 0.56% 80 min
October 615 75.5% 0.98% 72 min
November 452 80% 0.44% 69 min
December 412 73% 1.21% 57 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.