Best time to fly Raleigh/Durham to Baltimore

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

Best month

November

92.9% on time · 160 flights

Worst month

July

74.5% on time · 169 flights

Month Flights On time Cancelled When late, by
January 132 88.5% 7.58% 44 min
February 123 89.6% 6.5% 41 min
March 149 79.3% 2.68% 52 min
April 146 92.5% 0% 52 min
May 149 86.6% 0% 112 min
June 154 81.6% 1.3% 54 min
July 169 74.5% 4.73% 116 min
August 150 87.8% 1.33% 57 min
September 141 92.1% 0% 52 min
October 166 81.3% 0% 51 min
November 160 92.9% 3.75% 38 min
December 161 85.5% 1.24% 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.