Why temperature on higher altitude is cooler than on lower altitudes?

Question

you have snow on mountains whereas the montain surface is closer to sun than the base of mountain

Answer 1

The atmosphere retains heat, the thinner it becomes, the less heat it holds.

Answer 2

The proximety to the sun has nothing to do with anything...well anything on the earth anyways. It is colder at higher altitudes cause of the adiabatic lapse rate, this how the temperature changes with altitude. Long story short it has to do with how work is done and expansion and contraction of air.

As a quick "experiment" to kinda demonstrate this. Take a thick rubberband at room temperature. and expand it quickly and put it on your chin, it will feel colder then take it off your chin then let it go back to its normal size quickly and put it back on your chin, you should feel a faily drastic difference.

Answer 3

The simple way I think of it is that the air is colder higher up because there is less of it.

There are fewer molecules per square centimetre, so they bump into each other less often, so they don't heat up as much.