Best time to fly Wilmington to Washington

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

Best month

September

85.6% on time · 150 flights

Worst month

February

52.4% on time · 126 flights

Month Flights On time Cancelled When late, by
January 124 65.4% 16.13% 63 min
February 126 52.4% 16.67% 116 min
March 127 75.8% 4.72% 93 min
April 121 81.9% 3.31% 157 min
May 136 70.5% 1.47% 76 min
June 168 64.4% 10.12% 116 min
July 150 58.8% 9.33% 124 min
August 150 71.8% 5.33% 59 min
September 150 85.6% 2.67% 68 min
October 152 76% 1.32% 42 min
November 122 74.1% 3.28% 100 min
December 117 59.6% 2.56% 101 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.