Best time to fly Columbus to Washington

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

Best month

October

83.2% on time · 173 flights

Worst month

December

53.5% on time · 149 flights

Month Flights On time Cancelled When late, by
January 168 62.1% 8.93% 88 min
February 163 57.7% 4.29% 55 min
March 182 65.3% 3.3% 69 min
April 169 74.6% 0% 83 min
May 178 72.7% 1.12% 75 min
June 176 76.8% 3.41% 75 min
July 180 61.6% 10.56% 109 min
August 180 78.7% 1.11% 56 min
September 171 81.9% 0% 55 min
October 173 83.2% 0% 51 min
November 166 57.5% 3.61% 51 min
December 149 53.5% 3.36% 55 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.