Why Are Deserts Hot in the Day and Cold at Night?

Grand Parc – Bordeaux, France/Flickr/CC-BY-2.0

The heat that radiates from the sun and heats up the land begins to heat up the air and then escapes into the atmosphere due to the lack of clouds and humidity. This is the main reason that deserts can be hot during the day but cold during the night.

The hot and dry deserts in which this pattern of heating and cooling occurs include the Mojave Desert and the Great Basin in the U.S. and the Sonoran and Chihuahuan Deserts in Mexico. The seasons are generally warm throughout the year but get a lot hotter during the summer. Because of the lack of humidity in the area, the ground receives more than twice the radiation heat from the sun during the day and loses twice as much heat during the night in comparison to more humid environments.

Hot and dry deserts have a mean annual temperature of 20 to 25 degrees Celsius, and the extreme temperatures can range from 43 to 49.5 degrees Celsius during the day and minus 18 degrees Celsius at night. Because of the heat and the lack of rainfall, there are no large canopy trees to shade animals or plants. Most plants are stubby in height, such as ground-hugging shrubs, and there are very few large mammals because they are often not capable of storing enough water.