Best time to fly Houston to San Antonio

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

Best month

February

91.6% on time · 168 flights

Worst month

June

69% on time · 171 flights

Month Flights On time Cancelled When late, by
January 179 90.4% 1.12% 55 min
February 168 91.6% 0% 32 min
March 234 82.1% 2.14% 75 min
April 215 82.8% 0% 51 min
May 185 81.6% 0% 63 min
June 171 69% 0% 70 min
July 185 71.6% 1.08% 97 min
August 208 78.7% 0.48% 59 min
September 229 87.3% 0% 56 min
October 213 85.4% 0% 58 min
November 207 83.4% 0.97% 52 min
December 217 83.9% 0% 41 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.