Question: if heat rises why is it cold on top of a MOUNTAIN

Jonny Brooks-Bartlett answered on 13 Jun 2015:

Brlliant question and I didn’t actually know the answer to this question. But I did manage to find one here: https://www.highlightskids.com/science-questions/if-heat-rises-why-it-cold-top-mountains

You are right that hot air rises but one factor we often don’t take into account is pressure (mainly because it pressure is usually constant for most every day situations).
However pressure decreases as you go higher in the atmosphere. This means that the air is not as compressed and it expands. Gases cool when they expand and that’s why mountain tops are cold – hot air cools itself as it rises.
“The temperature goes down three or four degrees Fahrenheit for every thousand feet higher we go”