Best time to fly San Francisco to Sacramento

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

Best month

April

87.3% on time · 237 flights

Worst month

December

73.3% on time · 198 flights

Month Flights On time Cancelled When late, by
January 210 81% 2.38% 112 min
February 210 78.3% 3.33% 103 min
March 208 81.7% 0% 62 min
April 237 87.3% 0.42% 45 min
May 227 79.6% 0.44% 76 min
June 201 79.6% 0% 48 min
July 176 81.7% 0.57% 53 min
August 188 86.2% 0% 87 min
September 214 84.1% 0% 61 min
October 265 82.3% 0% 72 min
November 237 73.7% 8.02% 87 min
December 198 73.3% 1.52% 83 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.