Best time to fly Chicago to Cincinnati

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

Best month

September

84.4% on time · 77 flights

Worst month

July

58.7% on time · 78 flights

Month Flights On time Cancelled When late, by
January 65 77.8% 3.08% 59 min
February 60 78.3% 0% 60 min
March 94 64.5% 1.06% 71 min
April 94 81.7% 1.06% 44 min
May 95 76.8% 0% 62 min
June 99 69.1% 2.02% 53 min
July 78 58.7% 2.56% 54 min
August 80 83.5% 1.25% 44 min
September 77 84.4% 0% 32 min
October 78 74.4% 0% 47 min
November 61 78.3% 1.64% 67 min
December 63 66.7% 0% 77 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.