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 ORD record →

Best month

May

82.3% on time · 875 flights

Worst month

December

67.6% on time · 666 flights

Month Flights On time Cancelled When late, by
January 598 75.4% 2.51% 80 min
February 647 81% 0.62% 75 min
March 789 73.7% 2.92% 96 min
April 856 79% 2.1% 90 min
May 875 82.3% 1.03% 74 min
June 850 74.2% 1.88% 84 min
July 632 70.1% 2.69% 107 min
August 712 77.5% 2.11% 91 min
September 747 80.4% 0.13% 64 min
October 774 78.9% 0.26% 70 min
November 708 76.2% 2.26% 74 min
December 666 67.6% 0.9% 86 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.