Best time to fly Raleigh/Durham to Las Vegas

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

Best month

April

90% on time · 60 flights

Worst month

June

53.8% on time · 13 flights

Month Flights On time Cancelled When late, by
January 62 82.5% 8.06% 59 min
February 56 83.9% 0% 36 min
March 62 87.1% 0% 87 min
April 60 90% 0% 29 min
May 62 79% 0% 41 min
June 13 53.8% 0% 23 min
July 78 84.4% 1.28% 67 min
August 66 80.3% 0% 48 min
September 51 78.4% 0% 37 min
October 60 73.3% 0% 37 min
November 56 87.5% 0% 50 min
December 57 89.5% 0% 46 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.