How reliable is George Bush Intercontinental Houston Airport?

Across official performance history, flights from Houston left within 15 minutes of schedule about 79% of the time over 988,811 flights. That's a respectable but unspectacular operational record. Pair it with a moderate cancellation rate of 1.7%. When a departure does run late, the typical delay is around 15 minutes.

On weather, Houston is an unusually calm-weather airport year-round. August is the calmest stretch for flying, scoring 98 out of 100 for favorable conditions, while December is the most disruptive at 87, driven mainly by low visibility & fog and thunderstorms. The year is relatively steady, so no single month stands out as one to avoid on weather alone.

If you're connecting through IAH, give yourself room. Real itineraries sold through IAH bottom out around 65 minutes for a domestic connection, and international transfer wants roughly 95 minutes once immigration and a bag recheck are in the mix. Those are floors, not comfortable buffers — one inbound delay can erase them, so add margin when the connection matters.

None of this guarantees your specific flight — it’s the backdrop. To turn it into a booking, score real flights to Houston, read how we weigh it all in how the Peace of Mind Score works, and brush up with how to pick a reliable flight and avoiding weather delays.