Best time to fly Columbus to Chicago

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

Best month

September

92.6% on time · 230 flights

Worst month

March

74.6% on time · 178 flights

Month Flights On time Cancelled When late, by
January 184 81.4% 3.8% 49 min
February 165 85.8% 1.21% 45 min
March 178 74.6% 2.81% 65 min
April 178 84.8% 0% 70 min
May 183 85.2% 0% 54 min
June 238 79.2% 0.84% 65 min
July 250 78.5% 1.2% 75 min
August 240 89.6% 0% 75 min
September 230 92.6% 0% 38 min
October 235 89.3% 0.85% 48 min
November 208 84.8% 1.92% 48 min
December 212 77.4% 0% 58 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.