Best time to fly Atlanta to Key West

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

Best month

September

91.4% on time · 240 flights

Worst month

July

68.5% on time · 247 flights

Month Flights On time Cancelled When late, by
January 242 76.1% 3.31% 79 min
February 224 77.8% 0% 51 min
March 248 79.8% 2.42% 104 min
April 239 84.5% 0% 43 min
May 252 83.2% 0.79% 53 min
June 241 82.1% 2.49% 51 min
July 247 68.5% 3.64% 76 min
August 248 86.6% 3.23% 64 min
September 240 91.4% 2.5% 44 min
October 247 89.3% 1.21% 77 min
November 238 83.6% 1.26% 95 min
December 253 75% 0.79% 69 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.