Best time to fly Newark to Portland

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

Best month

September

91.4% on time · 176 flights

Worst month

July

67.6% on time · 186 flights

Month Flights On time Cancelled When late, by
January 73 84.5% 1.37% 50 min
February 89 77.1% 6.74% 60 min
March 119 78.4% 0.84% 49 min
April 117 70.9% 0% 68 min
May 133 77.1% 1.5% 141 min
June 176 69.9% 0% 69 min
July 186 67.6% 3.76% 85 min
August 184 78.3% 4.35% 66 min
September 176 91.4% 0.57% 66 min
October 171 84.1% 0% 51 min
November 115 72.8% 0.87% 76 min
December 124 67.7% 0% 66 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.