The Sahara Desert represents the extremity of Earth’s diverse biomes. Deserts, as the driest biomes, can vary in temperature from very cold to extremely hot. The coldest deserts are located in the Arctic and Antarctic, while the hottest, including the Sahara, are near or along the equator.
Covering most of Northern Africa, the Sahara is the largest hot desert on Earth, comparable in size to the United States or China. It experiences some of the most extreme temperatures globally, with summertime highs exceeding 104°F (40°C) and the highest recorded temperature at 136°F (58°C). Rainfall is scarce, particularly in the vast central region, where it averages less than 0.4 inches (10 millimeters) annually. Even in the wetter areas, annual rainfall does not exceed 10 inches (250 millimeters).
The formation of the Sahara is linked to plate tectonics and continental drift. Around 7 million years ago, the collision of the African and European plates, which led to the formation of the Alps, also closed the Tethys Sea. This change eliminated the ocean’s moderating influence on northern Africa’s climate, leading to the gradual desertification of the region and the birth of the Sahara.
In the Sahara, wind plays a crucial role as a geologic agent, shaping the landscape by eroding quartz-rich continental rocks and former ocean sediments. This process has created vast “seas” of sand that now dominate the desert’s topography. The Sahara stands as a testament to the dynamic forces of Earth’s geology and climate, continually reshaping the face of our planet.
