Best time to fly Wilmington to Chicago

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

Best month

October

93.5% on time · 31 flights

Worst month

November

50% on time · 2 flights

Month Flights On time Cancelled When late, by
January 4 66.7% 25% 26 min
February 37 91.9% 0% 22 min
March 66 83.9% 3.03% 80 min
April 57 83.9% 1.75% 65 min
May 79 86.1% 0% 51 min
June 182 66.7% 2.75% 79 min
July 148 58.3% 2.03% 65 min
August 132 66.4% 3.03% 94 min
September 37 89.2% 0% 46 min
October 31 93.5% 0% 33 min
November 2 50% 0% 103 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.