Best time to fly Mason City to Chicago

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

Best month

February

79.2% on time · 48 flights

Worst month

June

59.6% on time · 51 flights

Month Flights On time Cancelled When late, by
January 53 65.3% 7.55% 100 min
February 48 79.2% 0% 106 min
March 53 69.6% 13.21% 99 min
April 52 76.1% 11.54% 87 min
May 53 66.7% 3.77% 106 min
June 51 59.6% 7.84% 61 min
July 53 64% 5.66% 92 min
August 53 62% 5.66% 90 min
September 51 76.5% 0% 147 min
October 54 60.4% 0% 46 min
November 50 66% 6% 62 min
December 55 70.7% 25.45% 217 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.