Best time to fly Houston to Miami

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

Best month

October

86.1% on time · 564 flights

Worst month

July

62.7% on time · 586 flights

Month Flights On time Cancelled When late, by
January 664 81% 3.16% 91 min
February 583 78.9% 0.69% 106 min
March 680 71.7% 2.06% 108 min
April 624 81.2% 0.96% 99 min
May 642 73.2% 0.78% 107 min
June 582 74.3% 1.55% 79 min
July 586 62.7% 6.31% 92 min
August 593 71.5% 1.69% 85 min
September 529 82.3% 0.19% 92 min
October 564 86.1% 0.71% 92 min
November 637 81.9% 0.94% 59 min
December 667 76.1% 0.6% 78 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.