Best time to fly New York to Las Vegas

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

Best month

November

84.8% on time · 632 flights

Worst month

July

71.8% on time · 587 flights

Month Flights On time Cancelled When late, by
January 614 82.8% 2.12% 62 min
February 558 73.1% 4.66% 56 min
March 655 84.1% 0.76% 64 min
April 678 84% 0.15% 50 min
May 690 83% 0.87% 63 min
June 639 77.6% 0.78% 83 min
July 587 71.8% 4.77% 73 min
August 598 80.3% 1.34% 69 min
September 652 83.9% 0% 50 min
October 708 83.6% 0.71% 55 min
November 632 84.8% 0.79% 63 min
December 590 78.5% 1.36% 76 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.