Best time to fly San Francisco to Phoenix

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

Best month

March

84.1% on time · 452 flights

Worst month

June

64.5% on time · 384 flights

Month Flights On time Cancelled When late, by
January 376 81.6% 1.86% 80 min
February 361 81.3% 0.28% 60 min
March 452 84.1% 0% 89 min
April 432 69.6% 1.16% 78 min
May 417 68.5% 0.24% 85 min
June 384 64.5% 0.26% 62 min
July 356 71.7% 0.84% 89 min
August 341 78.6% 0.88% 64 min
September 342 77.5% 1.17% 54 min
October 367 72.7% 0% 66 min
November 390 68.3% 2.56% 66 min
December 425 74.8% 0.24% 96 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.