Lack of moisture: The Sahara desert is extremely dry, with very low humidity levels. This means there is little water vapor in the air to trap heat during the night. As a result, the heat that accumulates during the day quickly radiates back into space, causing temperatures to drop rapidly after sunset.
Clear skies: The Sahara desert often experiences clear skies, with minimal cloud cover. Clouds act as a blanket that traps heat near the Earth's surface, preventing it from escaping into the atmosphere. In the absence of clouds, the heat from the day is easily lost into outer space.
Thermal radiation: The desert sand has a low thermal capacity, meaning it does not retain heat well. As the sun sets, the sand rapidly releases the heat it absorbed during the day. This process is known as thermal radiation and contributes to the rapid temperature drop at night.
Wind: The Sahara desert is often characterized by strong winds, especially at night. These winds can further accelerate the cooling process by carrying away the warm air and replacing it with cooler air.
High elevation: Some parts of the Sahara desert are located at high elevations, which also contributes to lower temperatures. As elevation increases, the air becomes thinner and there is less atmospheric pressure. This allows heat to escape more easily, resulting in cooler temperatures.
Overall, the combination of low humidity, clear skies, thermal radiation, wind, and high elevation in the Sahara desert leads to significant temperature drops at night, despite the scorching temperatures experienced during the day.
