Best time to fly Portland to Nashville

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

Best month

July

90.9% on time · 66 flights

Worst month

November

77.6% on time · 58 flights

Month Flights On time Cancelled When late, by
January 37 86.1% 2.7% 26 min
February 40 87.2% 2.5% 62 min
March 58 87.9% 0% 35 min
April 60 80% 0% 34 min
May 62 87.1% 0% 56 min
June 64 82.8% 0% 35 min
July 66 90.9% 0% 53 min
August 63 82.5% 0% 61 min
September 60 81.7% 0% 42 min
October 61 88.5% 0% 20 min
November 58 77.6% 0% 42 min
December 62 83.9% 0% 31 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.