sunshine ranging from 68% in December to 79% in September and October, the city receives 3,285 hours of bright sunshine annually, making it one of the sunniest nationally. The monthly 24-hour average temperature ranges from in January to in July, while the annual mean is . The diurnal temperature variation is typically large, at about an average for the year. Administrative divisions Demographics , Hami had a population of about 580,000 of which 68.4% were Han Chinese and 31.6% ethnic minorities, mostly Uyghurs, Kazakhs, and Hui. As of 2015, 427,657 (76.6%) of the 616,711 residents of the county were Han Chinese, 109,072 (17.6%) were Uyghur, 55,550 (9.0%) were Kazakh and 17,588 (2.8%) were Hui. Economy The Hami area is known for its large amount of high quality raw resources with 76 kinds of metals already detected. The major mineral resources of this area include coal, iron, copper, nickel, gold. A newly discovered nickel deposit in Hami is estimated to contain reserves of over 15.8 million tons of the metal, it therefore ranks as China's second largest nickel mine. Around 900,000 tons of nickel has already been detected. Some local copper and nickel mining enterprises are reported to have begun operation, with Xinjiang Nonferrous Metals Group mining company running its nickel smelter crude production furnace at Hami Industrial Park. China is building a field of ICBM silos near Hami, about 380 km (240 miles) northwest of the another field near Yumen. Transport Hami is connected to Xinjiang and the rest of China by both high-speed and conventional rail links. The Lanzhou–Xinjiang High-Speed Railway, a passenger dedicated high speed rail line running from Lanzhou in Gansu Province to Ürümqi passes through the city. Hami is a stopping point for the Lanzhou–Xinjiang Railway and Ejin–Hami Railway, two lines that are part of trans-national transport corridors. The Lanzhou–Xinjiang Railway carries passengers and freight, connecting the rest of China to Central Asia and beyond as part of the New Eurasian Land Bridge through a border cross in Kazakhstan, and the Ejin–Hami Railway moves passengers and freight as part of a planned corridor beginning in the Bohai Gulf in North China to Torugart Pass on the border with Kyrgyzstan. A short rail line of transports potassium salts mined near Lop Nur to Hami. By road Hami is located along China National Highway 312, an east–west route of from Shanghai to Khorgas, Xinjiang in the Ili River