Best time to fly Detroit to Salt Lake City

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

Best month

September

92.7% on time · 123 flights

Worst month

December

55.6% on time · 124 flights

Month Flights On time Cancelled When late, by
January 119 65.5% 0% 71 min
February 108 79.4% 0.93% 59 min
March 123 68.3% 0% 58 min
April 121 85.1% 0% 40 min
May 148 86.4% 0.68% 74 min
June 149 78.5% 0% 75 min
July 167 81.9% 0.6% 73 min
August 149 84.6% 0% 36 min
September 123 92.7% 0% 29 min
October 124 92.7% 0% 38 min
November 119 91.6% 0% 34 min
December 124 55.6% 0% 57 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.