Best time to fly Manhattan/Ft. Riley to Chicago

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

Best month

September

93.3% on time · 30 flights

Worst month

December

60.3% on time · 60 flights

Month Flights On time Cancelled When late, by
January 37 68.6% 5.41% 232 min
February 45 82.2% 0% 73 min
March 62 73.3% 1.61% 73 min
April 114 82.7% 3.51% 70 min
May 121 90.8% 0.83% 64 min
June 94 75.6% 4.26% 188 min
July 62 67.2% 1.61% 99 min
August 38 75% 5.26% 100 min
September 30 93.3% 0% 151 min
October 56 69.6% 0% 75 min
November 59 79.6% 8.47% 51 min
December 60 60.3% 3.33% 156 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.