Best time to fly Washington to Houston

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

Best month

February

92.3% on time · 80 flights

Worst month

May

59.1% on time · 88 flights

Month Flights On time Cancelled When late, by
January 89 86.7% 6.74% 45 min
February 80 92.3% 2.5% 43 min
March 93 72.5% 2.15% 64 min
April 87 80.5% 0% 44 min
May 88 59.1% 0% 56 min
June 90 61.8% 1.11% 64 min
July 93 66.7% 5.38% 89 min
August 89 76.4% 0% 77 min
September 86 83.7% 0% 54 min
October 85 88.2% 0% 49 min
November 85 81.7% 3.53% 82 min
December 91 83.5% 0% 51 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.