Best time to fly Chicago to Eau Claire

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

Best month

September

85.4% on time · 50 flights

Worst month

July

57.7% on time · 52 flights

Month Flights On time Cancelled When late, by
January 107 65.7% 0.93% 87 min
February 95 69.1% 1.05% 99 min
March 106 66% 11.32% 128 min
April 103 68.4% 7.77% 122 min
May 107 74.5% 0.93% 68 min
June 103 66.3% 3.88% 88 min
July 52 57.7% 0% 68 min
August 54 67.3% 3.7% 71 min
September 50 85.4% 2% 46 min
October 54 77.8% 0% 122 min
November 50 68.1% 2% 78 min
December 87 59.5% 9.2% 169 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.