Best time to fly Portland to New York

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

Best month

March

95.2% on time · 62 flights

Worst month

July

69.4% on time · 93 flights

Month Flights On time Cancelled When late, by
January 62 83.3% 3.23% 27 min
February 56 88.2% 8.93% 23 min
March 62 95.2% 0% 34 min
April 60 93.2% 0% 20 min
May 87 91.8% 1.15% 188 min
June 90 84.3% 0% 99 min
July 93 69.4% 7.53% 77 min
August 93 82.6% 1.08% 61 min
September 90 78.4% 0% 37 min
October 93 81.1% 1.08% 47 min
November 66 89.2% 1.52% 37 min
December 62 95% 1.61% 49 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.