Best time to fly Oakland to Seattle

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

Best month

February

88.7% on time · 239 flights

Worst month

June

66.8% on time · 407 flights

Month Flights On time Cancelled When late, by
January 279 88.1% 0.72% 55 min
February 239 88.7% 0.42% 43 min
March 235 84% 1.7% 53 min
April 244 81.9% 0.41% 50 min
May 272 78.3% 0% 37 min
June 407 66.8% 0% 51 min
July 466 71.8% 0.43% 44 min
August 427 73.6% 0.47% 57 min
September 371 77.1% 0% 40 min
October 347 81.2% 0.29% 45 min
November 302 88.6% 1.66% 42 min
December 312 78.5% 0.32% 55 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.