Best time to fly Chicago to Madison

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

Best month

June

78% on time · 328 flights

Worst month

January

57.1% on time · 318 flights

Month Flights On time Cancelled When late, by
January 318 57.1% 2.52% 77 min
February 262 72.4% 0.38% 78 min
March 344 69.8% 10.47% 89 min
April 427 72.5% 5.39% 93 min
May 403 77.4% 0.99% 85 min
June 328 78% 3.96% 66 min
July 261 69.9% 4.21% 86 min
August 327 77.5% 2.14% 69 min
September 336 76.5% 0% 51 min
October 353 74.2% 0% 83 min
November 370 70.3% 10% 101 min
December 300 57.5% 4.33% 93 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.