Best time to fly San Diego to Portland

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

Best month

April

91.4% on time · 164 flights

Worst month

June

67.8% on time · 151 flights

Month Flights On time Cancelled When late, by
January 136 81.2% 2.21% 57 min
February 118 90.7% 0% 60 min
March 172 91.2% 1.16% 58 min
April 164 91.4% 1.22% 39 min
May 155 87.1% 0% 38 min
June 151 67.8% 1.32% 40 min
July 157 81.8% 1.91% 52 min
August 148 81.4% 2.03% 62 min
September 130 87.6% 0.77% 62 min
October 145 86.7% 1.38% 72 min
November 145 80.7% 0% 45 min
December 156 81.9% 0.64% 43 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.