Best time to fly Boston to Jacksonville

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

Best month

May

82.5% on time · 160 flights

Worst month

December

67.4% on time · 143 flights

Month Flights On time Cancelled When late, by
January 96 68.5% 6.25% 80 min
February 101 71.4% 9.9% 55 min
March 144 74.3% 2.08% 72 min
April 148 80.4% 0% 64 min
May 160 82.5% 0% 62 min
June 141 82.1% 0.71% 69 min
July 146 67.9% 6.16% 78 min
August 134 80.9% 2.24% 60 min
September 125 77% 2.4% 73 min
October 144 72.1% 2.78% 57 min
November 124 75% 0% 62 min
December 143 67.4% 1.4% 54 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.