Best time to fly Portland to Sacramento

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

Best month

January

90.2% on time · 278 flights

Worst month

June

75.6% on time · 387 flights

Month Flights On time Cancelled When late, by
January 278 90.2% 0.36% 35 min
February 266 87.2% 0.38% 44 min
March 320 85.3% 0% 58 min
April 318 83.3% 0.31% 60 min
May 333 83.4% 0.3% 51 min
June 387 75.6% 0.52% 57 min
July 368 79.7% 0.82% 60 min
August 339 83.7% 0.29% 49 min
September 309 86.7% 0% 40 min
October 322 84.5% 0% 53 min
November 273 85.6% 0.73% 51 min
December 298 76.8% 0% 54 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.