Landform and Geology

　　The total land area of Tianjin is 11,916.85 square kilometers, consisting of mainly plain and lowland. Constructional plain accounts for 93% of the total area of Tianjin. Lying at the transition zone between the northern Yanshan mountains and the coastal plain, its altitude gradually decreases from the north to the south. The average altitude in the north is 1,052m, the highest point being the 1,078.5m Jiushanding in Jixian County; the southeast coastal part, with an average altitude of no more than 3.5m, is the lowest point in the North China Plain.

　　Tianjin area came into being with the regression of the sea over a geological history of 2 billion years.

　　Natural Resources

　　Tianjin has a vast sea area and a rich supply of marine resources. Firstly, there are abundant oil and gas resources. In 2015, Bohai and Dagang Oilfields produced 34.9677 million tons of crude oil and 2.054 billion cubic meters of natural gas. Secondly, with its coastline stretching 153 kilometers, Tianjin has inexhaustible sea salt resources. Changlu Salt Field, a famous production base of sea salt in China.

　　Tianjin also possesses rich mineral resources. In addition to over 20 kinds of metallic minerals, including jimboite, manganese, gold, tungsten, molybdenum, copper, zinc, iron, etc., Tianjin also has non-metallic minerals such as cement limestone, barite, stacked stone, marble, natural stone, purple clay, medical stone, etc., highly promising for utilization.

　　Tianjin has substantial geothermal resources, whose water temperature ranges from 30 to 90℃. They are shallow and of high quality. Ten valuable geothermal areas have been discovered, with total hot water reserve of 110.36 billion cubic meters. They constitute the largest mid-and low-temperature geothermal field in China. Now, large-scale spa resorts have been built in Baodi, Dongli, Wuqing, Jinghai and other areas in Tianjin.

　　Tianjin boasts abundant land resources. Except for the mountainous and hilly areas in Jixian County, the land in Tianjin has soil which developed on deep sediments. In the coastal area on the lower reaches of the Haihe River, there is saline wasteland to be exploited. With favorable traffic conditions, these areas can be exploited at low expenses.

　　Tianjin enjoys a leading position in China in the exploitation and utilization of geothermal resources

　　There are altogether 140 geothermal plants in Tianjin, supplying heating to an area of 12 million square meters, accounting for 10% of the centralized heating area in Tianjin and 50% of the geothermal heating area in China. This can save 336,000 tons of raw coal, reduce emissions of 2,688 tons of coal dust, 5,712 tons of sulfur dioxide, 2,016 tons of nitrogen oxide, and 171,400 cubic meters of carbon monoxide.

　　Climate

　　Tianjin is located in the north temperate subhumid monsoon climate zone, with clearly-divided four seasons. In winter, it is cold and dry. In summer, the weather is characterized by high humidity and high temperature, usually with south wind. In spring, it is dry and windy, with sharp changes of temperature. In autumn, the weather is usually fine, with a breeze. Though mainly with continental climate characteristics, Tianjin climate sometimes shows features of maritime climate, with sea and land breezes due to the influence of Bohai Sea. In 2015, the average temperature of Tianjin is 13.6℃ .

　　The coldest month is January, with a monthly average temperature of -0.7℃ ; the hottest month is July, with an average temperature of 26.9 ℃ . The average annual precipitation is 563.8 millimeters.