Best time to fly Chicago to New Orleans

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

Best month

September

88.7% on time · 142 flights

Worst month

July

62.2% on time · 181 flights

Month Flights On time Cancelled When late, by
January 200 73.1% 1.5% 71 min
February 220 78% 0.45% 78 min
March 248 68.4% 6.85% 80 min
April 225 70.2% 3.11% 70 min
May 184 76.4% 0.54% 78 min
June 206 70.5% 2.43% 76 min
July 181 62.2% 0% 66 min
August 157 77.3% 1.91% 66 min
September 142 88.7% 0.7% 50 min
October 235 85.5% 0% 67 min
November 218 82.4% 3.67% 85 min
December 186 66.3% 0.54% 71 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.