Best time to fly Buffalo to Chicago

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

Best month

January

90% on time · 30 flights

Worst month

March

58.1% on time · 77 flights

Month Flights On time Cancelled When late, by
January 30 90% 0% 35 min
February 30 86.7% 0% 58 min
March 77 58.1% 3.9% 53 min
April 82 80.2% 0% 44 min
May 82 74.4% 0% 55 min
June 90 75% 2.22% 75 min
July 97 76.8% 1.03% 58 min
August 84 78.6% 0% 81 min
September 82 89% 0% 37 min
October 59 84.7% 0% 42 min
November 56 84.9% 5.36% 56 min
December 60 71.2% 1.67% 51 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.