Due to its very high elevation, Lhasa has a cool semi-arid climate (Köppen BSk) with frosty winters and mild summers, yet the valley location protects the city from intense cold or heat and strong winds. The city enjoys nearly 3,000 hours of sunlight annually and is thus sometimes called the "sunlit city" by Tibetans. The coldest month is January with an average temperature of −1.6 °C (29.1 °F) and the warmest month is June with a daily average of 16.0 °C (60.8 °F), though nights have generally been warmer in July. The annual mean temperature is 7.98 °C (46.4 °F), with extreme temperatures ranging from −16.5 to 30.4 °C (2 to 87 °F). Lhasa has an annual precipitation of 426 millimetres (16.8 in) with rain falling mainly in July, August and September. The driest month is January at 0.8 millimetres (0.03 in) and the wettest month is August, at 120.6 millimetres (4.75 in). The rainy season is widely regarded the "best" of the year as rains come mostly at night and Lhasa is still sunny during the daytime
