Best time to fly San Francisco to Atlanta

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

Best month

February

89% on time · 219 flights

Worst month

May

73.2% on time · 285 flights

Month Flights On time Cancelled When late, by
January 217 86.4% 1.84% 86 min
February 219 89% 0% 58 min
March 281 86.3% 2.85% 83 min
April 284 78.4% 0% 52 min
May 285 73.2% 0.35% 62 min
June 304 77.5% 0.66% 56 min
July 319 75.9% 0.63% 74 min
August 304 79.5% 0.33% 63 min
September 277 85.9% 0% 53 min
October 303 87.5% 0% 71 min
November 286 82.6% 1.05% 76 min
December 271 80.7% 2.21% 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.