Best time to fly Greer to Chicago

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

Best month

September

88.1% on time · 128 flights

Worst month

December

61.4% on time · 140 flights

Month Flights On time Cancelled When late, by
January 119 62.7% 6.72% 51 min
February 121 74.8% 1.65% 37 min
March 151 73.9% 8.61% 100 min
April 142 80.9% 3.52% 70 min
May 184 83.1% 2.17% 85 min
June 156 74.3% 3.21% 71 min
July 170 61.9% 1.18% 90 min
August 147 82.3% 4.08% 55 min
September 128 88.1% 1.56% 49 min
October 173 80.8% 0% 48 min
November 166 72% 9.64% 108 min
December 140 61.4% 4.29% 72 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.