Night air temperatures tend to be lower at higher elevations because there are fewer air molecules to absorb outgoing longwave radiation.

Question

Quizplus · Accepted Answer

At higher elevations, the air pressure is lower and there are fewer air molecules to absorb and re-emit the longwave radiation emitted by the Earth's surface. As a result, the energy is radiated back into space, leading to cooler nighttime temperatures.

Night Air Temperatures Tend to Be Lower at Higher Elevations