Best time to fly Green Bay to Detroit

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

Best month

June

94.4% on time · 125 flights

Worst month

March

74.2% on time · 162 flights

Month Flights On time Cancelled When late, by
January 172 74.3% 0% 97 min
February 121 82.6% 0% 94 min
March 162 74.2% 3.7% 75 min
April 153 84.8% 1.31% 106 min
May 175 85.6% 0.57% 83 min
June 125 94.4% 0% 156 min
July 87 79.3% 0% 104 min
August 99 82.7% 0% 71 min
September 105 92.4% 0% 50 min
October 171 90.6% 0% 61 min
November 173 82.6% 3.47% 90 min
December 168 74.7% 3.57% 143 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.