Best time to fly Seattle to Santa Rosa

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

Best month

April

90.7% on time · 43 flights

Worst month

June

63.7% on time · 102 flights

Month Flights On time Cancelled When late, by
January 40 66.7% 12.5% 48 min
February 22 65% 9.09% 57 min
March 24 75% 0% 52 min
April 43 90.7% 0% 28 min
May 87 83.9% 0% 44 min
June 102 63.7% 0% 51 min
July 121 71.9% 0% 52 min
August 122 72.7% 0.82% 60 min
September 120 88.2% 0% 37 min
October 60 90% 0% 77 min
November 74 86.5% 0% 52 min
December 62 70% 3.23% 40 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.