Best time to fly Houston to Los Angeles

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

Best month

September

86.6% on time · 440 flights

Worst month

July

78.2% on time · 454 flights

Month Flights On time Cancelled When late, by
January 437 86.1% 1.37% 66 min
February 398 85.6% 0% 52 min
March 446 85.7% 1.12% 104 min
April 437 82.3% 0.46% 59 min
May 422 84.1% 0.24% 61 min
June 397 79.2% 0.25% 58 min
July 454 78.2% 1.1% 79 min
August 442 86.2% 0.9% 52 min
September 440 86.6% 0% 56 min
October 493 84.6% 0% 57 min
November 446 80.6% 0.67% 59 min
December 448 84% 0.67% 61 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.