The temperature of the thermosphere gradually increases with height. Unlike the stratosphere beneath it, wherein a temperature inversion is due to the absorption of radiation by ozone, the inversion in the thermosphere occurs due to the extremely low density of its molecules.

Does temperature decrease in the thermosphere?

In the top layer of the atmosphere, the thermosphere, temperatures again rise with altitude due to absorption of ultraviolet sunlight. At the top of this layer, temperatures can vary from 500 C (932 F) to 2,000 C (3,632 F) or higher.

Why does the temperature rise in the thermosphere?

While still extremely thin, the gases of the thermosphere become increasingly denser as one descends toward the earth. As such, incoming high energy ultraviolet and x-ray radiation from the sun begins to be absorbed by the molecules in this layer and causes a large temperature increase.