Temperature decreases with altitude in two of Earth's atmospheric regions: the troposphere and the mesosphere. The troposphere is the region closest to the ground, and the mesosphere is just above the ozone layer. We humans live in the troposphere, and nearly all weather occurs in this lowest layer. Most clouds appear here, mainly because 99% of the water vapor in the atmosphere is found in the troposphere. Air pressure drops, and temperatures get colder, as you climb higher in the troposphere. The mesosphere lies above the stratosphere and extends to an altitude of about 85 km. This is layer is often referred to as the cold layer, as the lowest readings in the atmosphere are found here. Temperature decreases with height, reaching a minimum average value of -90 ºC at the top of the layer. The troposphere is the lowest layer of the atmosphere. In it, temperature decreases with altitude. The troposphere gets some of its heat directly from the sun. Most, however, comes from Earth's surface.

The top of the mesosphere is the coldest area of the Earth's atmosphere because temperature may locally decrease to as low as 100 K (-173°C). The layers from closest to the Earth's surface to further away are the troposphere, stratosphere, mesosphere, thermosphere (with the ionosphere), and exosphere. The temperature increases at first then decreases, and then begins to increase again through the different layers. The troposphere and the stratosphere are the two lowest layers of the atmosphere. The troposphere is the layer next to Earth's surface. On the average, it extends 11 km to the top of the troposphere which is called the tropopause. In the troposphere, the temperature generally decreases with altitude. Located between about 50 and 80 kilometers (31 and 50 miles) above Earth's surface, the mesosphere gets progressively colder with altitude. In fact, the top of this layer is the coldest place found within the Earth system, with an average temperature of about minus 85 degrees Celsius (minus 120 degrees Fahrenheit). The thermosphere is above the mesosphere but is actually the hottest layer due to the absorption of intense x-rays and ultraviolet radiation. Thus, the mesosphere lacks radiation absorption from below and above, making it the coldest layer. As the density of the gases in this layer decrease with height, the air becomes thinner. Therefore, the temperature in the troposphere also decreases with height in response. As one climbs higher, the temperature drops from an average around 62°F (17°C) to -60°F (-51°C) at the tropopause.