Best time to fly Washington to Knoxville

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

Best month

September

82.4% on time · 172 flights

Worst month

December

59% on time · 143 flights

Month Flights On time Cancelled When late, by
January 163 62.8% 11.04% 58 min
February 162 61.1% 8.02% 109 min
March 182 63.4% 3.85% 111 min
April 178 73.3% 1.12% 96 min
May 186 69.3% 3.76% 65 min
June 179 64.7% 6.7% 140 min
July 181 61.8% 6.08% 106 min
August 177 73.2% 5.08% 104 min
September 172 82.4% 0.58% 65 min
October 178 75.3% 0% 58 min
November 191 78.3% 1.05% 68 min
December 143 59% 2.8% 99 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.