It is the largest salt pan of the Sahara Desert, with a surface area of over 7,000 km2 (some sources state 5,000 km2). The site has a typical hot desert climate. Due to the harsh climate with mean annual rainfall of below 100 mm and daytime temperatures sometimes reaching 50 °C (122 °F) or more during summer with dense solar radiation, water evaporates from the lake. In summer Chott el Djerid is almost entirely dried up, and numerous fata morganas occur.