Best time to fly Charlotte to Portland

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

Best month

January

92.3% on time · 31 flights

Worst month

July

70.3% on time · 94 flights

Month Flights On time Cancelled When late, by
January 31 92.3% 16.13% 48 min
February 28 80% 7.14% 193 min
March 31 71% 0% 126 min
April 54 81.5% 0% 48 min
May 75 70.7% 0% 78 min
June 94 71.3% 0% 105 min
July 94 70.3% 3.19% 64 min
August 79 74.4% 1.27% 61 min
September 81 90% 1.23% 71 min
October 78 84.4% 0% 69 min
November 32 75% 0% 120 min
December 31 74.2% 0% 41 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.