Best time to fly Chicago to Cedar Rapids/Iowa City

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

Best month

September

81.8% on time · 426 flights

Worst month

July

55.6% on time · 349 flights

Month Flights On time Cancelled When late, by
January 429 70.3% 1.63% 78 min
February 389 68.7% 0.77% 79 min
March 397 64.3% 6.8% 81 min
April 444 70.6% 4.95% 75 min
May 497 73.6% 1.01% 74 min
June 438 72.5% 2.05% 80 min
July 349 55.6% 2.58% 85 min
August 469 68.9% 2.35% 62 min
September 426 81.8% 0.47% 47 min
October 413 76.8% 0% 52 min
November 344 73.6% 4.07% 83 min
December 355 64.4% 7.89% 124 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.