Best time to fly Nashville to Portland

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

Best month

August

90.5% on time · 63 flights

Worst month

June

68.8% on time · 64 flights

Month Flights On time Cancelled When late, by
January 37 85.7% 5.41% 41 min
February 40 79.5% 2.5% 47 min
March 58 78.9% 0% 37 min
April 60 73.3% 0% 68 min
May 62 79% 0% 46 min
June 64 68.8% 0% 48 min
July 66 89.4% 0% 92 min
August 63 90.5% 0% 41 min
September 60 88.3% 0% 56 min
October 61 73.8% 0% 61 min
November 58 75.9% 0% 41 min
December 62 77% 1.61% 36 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.