Best time to fly Cedar Rapids/Iowa City to Chicago

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

Best month

September

83% on time · 426 flights

Worst month

December

64.6% on time · 353 flights

Month Flights On time Cancelled When late, by
January 431 74.5% 1.86% 89 min
February 388 73.7% 1.03% 110 min
March 396 69.5% 6.31% 105 min
April 444 72.7% 4.95% 96 min
May 496 80.6% 1.41% 72 min
June 439 73.8% 2.73% 111 min
July 349 67.1% 2.58% 79 min
August 469 70.8% 2.35% 67 min
September 426 83% 0.47% 56 min
October 412 76.9% 0% 50 min
November 344 72% 4.65% 65 min
December 353 64.6% 8.78% 91 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.