Best time to fly San Diego to Denver

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

Best month

January

85.3% on time · 928 flights

Worst month

June

67.8% on time · 983 flights

Month Flights On time Cancelled When late, by
January 928 85.3% 1.19% 65 min
February 851 84.1% 0.24% 58 min
March 988 83% 0.91% 64 min
April 942 81% 0.32% 62 min
May 979 75.7% 0.72% 63 min
June 983 67.8% 0.71% 67 min
July 957 69% 0.52% 68 min
August 917 74.5% 0.76% 54 min
September 870 82.1% 0.34% 57 min
October 1,026 77.4% 0.78% 62 min
November 986 82.4% 1.83% 55 min
December 988 74.8% 1.82% 69 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.