Best time to fly Boston to New York

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

Best month

August

86.5% on time · 568 flights

Worst month

March

66% on time · 616 flights

Month Flights On time Cancelled When late, by
January 543 80.9% 9.58% 86 min
February 550 82.7% 9.82% 64 min
March 616 66% 11.2% 68 min
April 642 78.8% 0.47% 70 min
May 666 80.9% 2.7% 58 min
June 661 81.2% 4.39% 86 min
July 592 74.7% 11.82% 90 min
August 568 86.5% 1.94% 65 min
September 634 77.5% 3.15% 65 min
October 674 71.1% 4.45% 89 min
November 599 76.2% 4.67% 83 min
December 506 75.9% 5.73% 87 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.