Best time to fly St. Louis to Houston

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

Best month

February

91.6% on time · 215 flights

Worst month

June

68.7% on time · 265 flights

Month Flights On time Cancelled When late, by
January 214 84.7% 5.14% 51 min
February 215 91.6% 0% 50 min
March 278 77.6% 0% 69 min
April 256 83.6% 0% 47 min
May 261 75.6% 0.38% 53 min
June 265 68.7% 0.75% 50 min
July 287 72.3% 2.44% 64 min
August 259 78.1% 0.39% 67 min
September 250 86.3% 0.4% 33 min
October 258 83.7% 0% 56 min
November 252 84.1% 0% 57 min
December 273 77.4% 0.37% 47 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.