Best time to fly Washington to Indianapolis

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

Best month

January

93.1% on time · 62 flights

Worst month

March

72.8% on time · 92 flights

Month Flights On time Cancelled When late, by
January 62 93.1% 6.45% 117 min
February 70 84.3% 0% 27 min
March 92 72.8% 0% 135 min
April 82 91.5% 0% 161 min
May 92 90.1% 1.09% 49 min
June 85 85.9% 0% 83 min
July 92 73.9% 3.26% 84 min
August 93 81.7% 0% 50 min
September 89 87.6% 0% 54 min
October 86 86% 0% 123 min
November 87 83.7% 1.15% 87 min
December 62 77% 1.61% 58 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.