Best time to fly Seattle to Oakland

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

Best month

February

82.4% on time · 136 flights

Worst month

August

64.1% on time · 199 flights

Month Flights On time Cancelled When late, by
January 147 82.1% 1.36% 44 min
February 136 82.4% 0% 50 min
March 124 76% 2.42% 57 min
April 120 81.7% 0% 65 min
May 124 75.6% 0.81% 41 min
June 186 69.9% 0% 63 min
July 233 65.4% 0.86% 58 min
August 199 64.1% 0.5% 47 min
September 166 71.1% 0% 38 min
October 178 79.7% 0.56% 42 min
November 153 79.3% 1.96% 50 min
December 151 64.7% 0.66% 50 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.