Best time to fly San Jose to Salt Lake City

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

Best month

January

95.7% on time · 254 flights

Worst month

June

89.2% on time · 335 flights

Month Flights On time Cancelled When late, by
January 254 95.7% 0% 130 min
February 249 92.7% 0.4% 58 min
March 284 92.2% 0.35% 64 min
April 274 92.3% 0% 50 min
May 328 91.5% 0% 83 min
June 335 89.2% 0.3% 108 min
July 344 89.9% 1.74% 73 min
August 330 90.9% 0.3% 122 min
September 320 93.4% 0% 68 min
October 334 92.5% 0% 49 min
November 309 92.5% 0.97% 98 min
December 275 92.7% 0.73% 51 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.