Best time to fly Kona to San Francisco

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

Best month

September

93.5% on time · 77 flights

Worst month

October

71.2% on time · 67 flights

Month Flights On time Cancelled When late, by
January 89 82% 0% 42 min
February 79 85.5% 1.27% 42 min
March 100 78.9% 5% 40 min
April 97 86.5% 0% 67 min
May 104 78.4% 1.92% 36 min
June 146 85.6% 0% 68 min
July 84 86.9% 0% 134 min
August 83 81.9% 0% 58 min
September 77 93.5% 0% 86 min
October 67 71.2% 1.49% 62 min
November 62 83.9% 0% 142 min
December 91 84.4% 1.1% 75 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.