Best time to fly Denver to San Diego

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

Best month

February

84.1% on time · 460 flights

Worst month

June

65% on time · 525 flights

Month Flights On time Cancelled When late, by
January 500 81.9% 0.2% 53 min
February 460 84.1% 0% 57 min
March 537 82.6% 1.49% 68 min
April 508 84% 0.2% 41 min
May 515 77.2% 0.19% 49 min
June 525 65% 0.38% 54 min
July 458 65.1% 0.87% 67 min
August 436 69.6% 0.46% 61 min
September 411 72.7% 0.73% 69 min
October 532 73.4% 0.19% 43 min
November 529 79.5% 2.46% 51 min
December 538 70.7% 0.56% 59 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.