of hot water, unique potential of clean and renewable geothermal energy at the surface of up to 65 square kilometers. The natural reservoir is at a depth of 500 to 800 meters, and the estimated capacity is about 400 million cubic meters of thermal mineral water. Climate Niš has a humid subtropical climate, but with continental influences. Average annual temperature in the area of Niš is . July is the warmest month of the year, with an average of . The coldest month is January, averaging at . The average of the annual rainfall is . The average barometer value is 992.74 mb. On average, there are 134 days with rain and snow cover lasts for 41 days. Demographics According to the final results from the 2011 census, the population of city proper of Niš was 183,164, while its administrative area had a population of 260,237. The city of Niš has 87,975 households with 2,96 members on average, while the number of homes is 119,196. Religion structure in the city of Niš is predominantly Serbian Orthodox (240,765), with minorities like Muslims (2,486), Catholics (809), Protestants (258), Atheists (109) and others. Most of the population speaks Serbian language (249,949). The composition of population by sex and average age: Male – 126,645 (40.90 years) and Female – 133,592 (42.81 years). A total of 120,562 citizens (older than 15 years) have secondary education (53.81%), while the 51,471 citizens have higher education (23.0%). Of those with higher education, 34,409 (15.4%) have university education. Ethnic composition The ethnic composition of the city of Niš: Administrative divisions Economy The city of Niš is the administrative, industrial, commercial, financial and cultural center of the south-eastern part of Republic of Serbia. The position of Niš is strategically important, at the intersection of European highway and railway networks connecting Europe with Asia. Niš is easily accessible, having an airport – Niš Constantine the Great Airport and being a point of intersection of numerous railroad and highway lines. It is in Niš that the trunk road running from the north down the Morava River valley forks into two major lines: the south one, leading to Thessalonica and Athens, along the Vardar River valley, and the east one, running along the Nišava and the Marica, leading towards Sofia and Istanbul, and further on, towards the Near East. These roads have been widely known from ancient times, because they represented the beaten