Jenny Ribble submitted a handmade Ask Todd asking "If heat rises, why is it so cold in the mountains?"
Well Jenny, that's a great question!
It has to do with two things: air density and altitude.
Air is a poor insulator of heat in general, and is heated from below, from the ground up. So the sun heats the ground first, then the air right above it.
But as you move further away from the ground up into the atmosphere, the heat is filtered out and greatly diminished because the air is less dense. Less dense air cannot hold as much heat.
Higher altitudes have thinner air as well so this is why the mountains are colder.