Best time to fly Chicago to State College

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

Best month

July

82.8% on time · 65 flights

Worst month

April

62.8% on time · 90 flights

Month Flights On time Cancelled When late, by
January 45 74.4% 2.22% 46 min
February 37 69.7% 8.11% 33 min
March 105 68.9% 0% 70 min
April 90 62.8% 2.22% 87 min
May 110 76.6% 1.82% 103 min
June 103 74.7% 3.88% 51 min
July 65 82.8% 1.54% 63 min
August 70 78.6% 0% 96 min
September 83 80.7% 0% 70 min
October 110 80.7% 0% 47 min
November 102 72% 1.96% 75 min
December 46 66.7% 2.17% 72 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.