Best time to fly Louisville to Atlanta

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

Best month

September

98.6% on time · 222 flights

Worst month

December

84.6% on time · 216 flights

Month Flights On time Cancelled When late, by
January 191 86.4% 3.66% 115 min
February 194 91.7% 0.52% 54 min
March 231 87.3% 4.76% 100 min
April 240 94% 1.67% 74 min
May 263 90% 1.52% 74 min
June 236 88.1% 0.42% 85 min
July 230 86% 0.43% 72 min
August 241 92.5% 0.83% 80 min
September 222 98.6% 0% 102 min
October 230 93.9% 0% 53 min
November 213 85.6% 1.88% 105 min
December 216 84.6% 3.7% 115 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.