Best time to fly Nashville to Seattle

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

Best month

February

84.2% on time · 76 flights

Worst month

December

55.1% on time · 90 flights

Month Flights On time Cancelled When late, by
January 81 68% 7.41% 43 min
February 76 84.2% 0% 67 min
March 91 71.1% 1.1% 59 min
April 118 83.9% 0% 50 min
May 142 79.4% 0.7% 46 min
June 177 69.9% 2.26% 69 min
July 188 72% 0.53% 60 min
August 176 63.8% 1.14% 51 min
September 135 74.8% 0% 45 min
October 117 77.2% 1.71% 46 min
November 88 76.1% 0% 46 min
December 90 55.1% 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.