Best time to fly Washington to Key West

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

Best month

April

88.2% on time · 120 flights

Worst month

December

71.9% on time · 120 flights

Month Flights On time Cancelled When late, by
January 124 77% 8.06% 50 min
February 112 81.8% 0.89% 44 min
March 124 79.7% 2.42% 40 min
April 120 88.2% 0% 70 min
May 94 78.5% 1.06% 49 min
June 68 83.6% 0% 29 min
July 62 79% 0% 41 min
August 62 81.7% 3.23% 33 min
September 64 85.2% 3.13% 40 min
October 66 84.6% 1.52% 47 min
November 114 78.9% 0% 65 min
December 120 71.9% 0.83% 60 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.