Best time to fly Charleston to Washington

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

Best month

September

85.5% on time · 293 flights

Worst month

February

62.9% on time · 293 flights

Month Flights On time Cancelled When late, by
January 309 74.1% 14.56% 82 min
February 293 62.9% 10.92% 94 min
March 328 68.3% 7.01% 77 min
April 324 77.4% 1.54% 123 min
May 331 70.7% 1.81% 94 min
June 295 70.7% 4.75% 149 min
July 303 67.2% 9.9% 87 min
August 303 76.4% 4.95% 85 min
September 293 85.5% 1.02% 96 min
October 301 82.3% 0.33% 58 min
November 283 83.2% 2.47% 106 min
December 286 75% 3.5% 81 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.