Best time to fly Las Vegas to Boston

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

Best month

November

85.7% on time · 258 flights

Worst month

July

72.1% on time · 235 flights

Month Flights On time Cancelled When late, by
January 277 81.9% 2.17% 77 min
February 270 75.6% 4.44% 71 min
March 340 80.5% 0.59% 59 min
April 338 83.3% 0.3% 77 min
May 338 75.8% 0.3% 71 min
June 239 78.4% 0.42% 89 min
July 235 72.1% 2.98% 81 min
August 245 75.9% 0.82% 82 min
September 306 72.6% 0% 84 min
October 341 77.3% 0% 82 min
November 258 85.7% 0% 105 min
December 259 80.4% 1.16% 64 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.