Best time to fly Boston to Newark

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

Best month

February

86.2% on time · 301 flights

Worst month

July

60.1% on time · 331 flights

Month Flights On time Cancelled When late, by
January 297 82.5% 7.41% 80 min
February 301 86.2% 8.64% 84 min
March 352 78.2% 2.27% 62 min
April 348 84.8% 0% 44 min
May 348 81.2% 0.57% 63 min
June 327 77.6% 3.06% 99 min
July 331 60.1% 10.57% 97 min
August 330 65.4% 1.82% 78 min
September 336 70.9% 2.98% 83 min
October 332 62.7% 3.61% 75 min
November 327 78.6% 10.09% 96 min
December 277 71% 1.81% 79 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.