Best time to fly Philadelphia to Atlanta

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

Best month

September

85.1% on time · 918 flights

Worst month

July

67.4% on time · 1,048 flights

Month Flights On time Cancelled When late, by
January 844 75.6% 6.16% 76 min
February 814 78.8% 3.19% 67 min
March 931 80.7% 2.58% 68 min
April 961 80.4% 1.04% 86 min
May 1,007 74.2% 0.89% 72 min
June 1,060 73.4% 2.17% 79 min
July 1,048 67.4% 3.82% 91 min
August 1,029 72.8% 2.43% 78 min
September 918 85.1% 0.44% 52 min
October 964 84.4% 0.1% 66 min
November 942 84.3% 1.7% 77 min
December 970 75.4% 2.06% 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.