Best time to fly Washington to Cedar Rapids/Iowa City

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

Best month

October

89.8% on time · 88 flights

Worst month

November

70% on time · 61 flights

Month Flights On time Cancelled When late, by
January 62 76.8% 9.68% 85 min
February 56 73.1% 7.14% 78 min
March 62 71.7% 3.23% 113 min
April 60 80% 0% 37 min
May 61 86.7% 1.64% 53 min
June 60 83.3% 0% 33 min
July 92 76.7% 6.52% 103 min
August 93 79.1% 2.15% 80 min
September 86 86.7% 3.49% 61 min
October 88 89.8% 0% 55 min
November 61 70% 1.64% 67 min
December 62 71.9% 4.84% 65 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.