Best time to fly Baltimore to Raleigh/Durham

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

Best month

September

89.4% on time · 142 flights

Worst month

July

71% on time · 169 flights

Month Flights On time Cancelled When late, by
January 132 85.8% 9.09% 40 min
February 123 84.5% 5.69% 34 min
March 149 77.2% 2.68% 46 min
April 146 87% 0% 63 min
May 149 81.9% 0% 63 min
June 154 80.3% 1.3% 61 min
July 169 71% 4.14% 95 min
August 149 78.9% 1.34% 52 min
September 142 89.4% 0% 77 min
October 167 76.6% 0% 55 min
November 160 81.8% 3.75% 56 min
December 161 79.7% 1.86% 43 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.