Best time to fly Detroit to Raleigh/Durham

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

Best month

September

88.3% on time · 259 flights

Worst month

December

74.3% on time · 239 flights

Month Flights On time Cancelled When late, by
January 207 81.4% 3.86% 44 min
February 201 84.6% 0% 54 min
March 252 84.7% 1.59% 56 min
April 257 88.2% 0.78% 68 min
May 265 84.8% 0.75% 58 min
June 268 84.5% 1.12% 72 min
July 296 78.5% 3.72% 81 min
August 293 81.8% 1.37% 67 min
September 259 88.3% 0.77% 54 min
October 273 87.8% 0.73% 54 min
November 277 87.7% 0.36% 55 min
December 239 74.3% 0.84% 53 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.