Best time to fly Kansas City to Salt Lake City

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

Best month

May

94.1% on time · 87 flights

Worst month

December

76.4% on time · 90 flights

Month Flights On time Cancelled When late, by
January 65 87.7% 0% 33 min
February 65 87.1% 4.62% 66 min
March 87 89.2% 4.6% 75 min
April 86 90.6% 0% 36 min
May 87 94.1% 1.15% 36 min
June 86 89.5% 0% 59 min
July 92 87.9% 1.09% 102 min
August 91 91.1% 1.1% 46 min
September 85 91.8% 0% 79 min
October 91 83.3% 0% 66 min
November 87 79.3% 0% 68 min
December 90 76.4% 1.11% 50 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.