Best time to fly St. Louis to Atlanta

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

Best month

October

92.2% on time · 642 flights

Worst month

July

74.6% on time · 649 flights

Month Flights On time Cancelled When late, by
January 543 88.1% 6.63% 99 min
February 501 86.5% 0.4% 73 min
March 565 82.3% 1.59% 62 min
April 584 85.7% 1.54% 79 min
May 632 80.7% 0.79% 61 min
June 649 81% 1.39% 70 min
July 649 74.6% 2.47% 91 min
August 630 88.6% 0.95% 66 min
September 602 91.7% 0.17% 43 min
October 642 92.2% 0.16% 47 min
November 560 87.6% 1.61% 66 min
December 603 81.4% 0.83% 68 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.