everybody knows that warm air rises. so it might seem that air temperature should be higher at the tops?

Question

of mountains than down below. but the opposite is often the case. why?

Answer 1

the air is thinner. temperature is a measurement of the average random kinetic energy of molecules. if there are fewer molecules around, not only are fewer moving to be measured, but those that are left have fewer opportunities to run into other molecules and cause hem to move. therefore the temperature is cooler at higher elevations for the same general weather conditions.

Answer 2

The atmosphere is way more complex than that and "warm air rises" is only one of the rules the atmosphere follows.

At high altitudes, the air is thinner, and therefore has less capacity to hold heat.

Also, the action of rising expends some of the warm air's energy, cooling it. the higher it goes, the less heat it will retain.

Answer 3

Warm air only rises when surrounded by cooler air which is more dense. Air is cooler high up because the pressure is reduced, which causes cooling.