Best time to fly Chicago to Wilmington

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

Best month

September

94.6% on time · 37 flights

Worst month

January

33.3% on time · 4 flights

Month Flights On time Cancelled When late, by
January 4 33.3% 25% 38 min
February 38 86.8% 0% 36 min
March 66 68.3% 4.55% 77 min
April 57 83.6% 3.51% 44 min
May 78 88.3% 1.28% 56 min
June 182 76.5% 1.1% 65 min
July 148 67.6% 0% 62 min
August 132 80.3% 0% 79 min
September 37 94.6% 0% 65 min
October 31 93.5% 0% 35 min
November 2 50% 0% 32 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.