Best time to fly Chicago to Knoxville

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

Best month

September

81.9% on time · 397 flights

Worst month

March

59.5% on time · 274 flights

Month Flights On time Cancelled When late, by
January 240 65% 5.83% 96 min
February 219 64.2% 0.46% 82 min
March 274 59.5% 6.2% 90 min
April 289 74.8% 2.42% 86 min
May 317 73.4% 1.58% 73 min
June 432 66.5% 1.62% 79 min
July 421 66.2% 3.09% 93 min
August 398 72.7% 1.51% 94 min
September 397 81.9% 0.76% 64 min
October 470 76.8% 0.21% 81 min
November 310 73.4% 4.52% 90 min
December 281 67.4% 2.85% 139 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.