The temperature drop in the atmosphere (more precisely the troposphere) is approx 10K per km, which is known as the lapse rate (see https://en.m.wikipedia.org/wiki/Lapse_rate). However, in the stratosphere the temperature will rise again as a function of UV absorption at ozone.

The temperature drop in the atmosphere (more precisely the troposphere) is approx 10 K per km (when assuming a dry atmosphere, and about 7 K for the average atmosphere, see https://en.m.wikipedia.org/wiki/Lapse_rate), which is known as the lapse rate. However, in the stratosphere the temperature will rise again as a function of UV absorption at ozone.