Best time to fly Birmingham to Chicago

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

There is not yet enough of the year on record for this route to say anything about seasons. The months below are shown as recorded.

Month Flights On time Cancelled When late, by
January 30 93.1% 0% 23 min
February 27 88.9% 0% 249 min
March 31 83.3% 3.23% 40 min
April 33 93.9% 0% 40 min
May 35 82.4% 0% 25 min
June 30 86.7% 0% 39 min
July 57 87.7% 0% 92 min
August 48 80.4% 4.17% 39 min
September 47 91.5% 0% 64 min
October 56 82.1% 0% 45 min
November 45 78.6% 4.44% 33 min
December 44 83.7% 0% 64 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.