The Dead Sea is a salt lake between Israel to the west, and Jordan to the east. It is 420 metres (1,378 ft) below sea level, and its shores are the lowest point on the surface of the Earth on dry land. The Dead Sea is 330 m (1,083 ft) deep, the deepest hypersaline lake in the world. It is also the world’s second saltiest body of water, after Lake Asal in Djibouti, with 30 percent salinity. It is 8.6 times saltier than the ocean. Israeli experts say that it is nine times saltier than the Mediterranean Sea (31.5% salt versus 3.5% for the Mediterranean). The Dead Sea is 67 kilometres (42 mi) long and 18 kilometres (11 mi) wide at its widest point. It lies in the Jordan Rift Valley, and its main tributary is the Jordan River.
The Dead Sea’s climate offers year-round sunny skies and dry air with low pollution. It has less than 100 millimetres (3.94 in) mean annual rainfall and a summer average temperature between 32 and 39 °C (90-102°F). Winter average temperatures range between 20 and 23 °C (68-74°F). The region has weakened ultraviolet radiation, particularly the UVB (erythrogenic rays), and an atmosphere characterized by a high oxygen content due to the high barometric pressure. The shore is the lowest dry place in the world. Proximity to the sea affects temperatures nearby because of the moderating effect a large body of water has on climate. During the winter months, sea temperatures tend to be higher than land temperatures, and vice versa during the summer months. This is the outcome of slow penetration of the sun’s rays into the sea, which is a huge mass that takes a long time to warm up.