Best time to fly Chicago to Rochester

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

Best month

October

86.5% on time · 37 flights

Worst month

March

50.9% on time · 58 flights

Month Flights On time Cancelled When late, by
January 27 74.1% 0% 55 min
February 27 74.1% 0% 64 min
March 58 50.9% 1.72% 51 min
April 57 76.4% 3.51% 38 min
May 57 75% 0% 53 min
June 86 61.2% 1.16% 64 min
July 93 66.3% 1.08% 64 min
August 72 70% 2.78% 58 min
September 68 82.4% 0% 38 min
October 37 86.5% 0% 52 min
November 27 69.2% 3.7% 53 min
December 29 70.4% 3.45% 49 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.