Best time to fly Chicago to Memphis

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

Best month

September

80.5% on time · 349 flights

Worst month

December

65.8% on time · 308 flights

Month Flights On time Cancelled When late, by
January 304 70.7% 6.91% 61 min
February 323 71% 0.62% 62 min
March 373 71.4% 3.49% 80 min
April 406 75.2% 3.2% 64 min
May 412 75.2% 0.97% 67 min
June 452 68.1% 1.55% 73 min
July 381 69.9% 1.84% 63 min
August 403 75.4% 1.99% 61 min
September 349 80.5% 0.29% 41 min
October 321 80.3% 0.31% 47 min
November 332 75.8% 4.22% 50 min
December 308 65.8% 0.97% 80 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.