Most of the country is in the northern temperate zone. There are complex climatic patterns ranging from the cold-temperate north to the tropical south, with subarctic-like temperatures in the Himalaya Mountains, resulting in a temperature difference of some 40E C from north to south. Temperatures range from –30E C in the north in January to 28E C in the south in July. Annual precipitation varies significantly from region to region, with a high of 1,500 millimeters annually along the southeastern coast and a low of fewer than 50 millimeters in the northwest. There is an alternating wet monsoon in the summer and a dry monsoon in winter. North China and southward are affected by the seasonal cold, dry winds from Siberia and the Mongolia Plateau between September/October and March/April. Summer monsoon winds bring warm and wet currents into South China and northward.
China has substantial mineral reserves and is the world’s largest producer of antimony, natural graphite, tungsten, and zinc. Other major minerals are bauxite, coal, crude petroleum, diamonds, gold, iron ore, lead, magnetite, manganese, mercury, molybdenum, natural gas, phosphate rock, tin, uranium, and vanadium. With its vast mountain ranges, China’s hydropower potential is the largest in the world.
Based on 2005 estimates, 14.86 percent (about 1.4 million square kilometers) of China’s land is arable. About 1.3 percent (some 116,580 square kilometers) is planted to permanent crops. With comparatively little land planted to permanent crops, intensive agricultural techniques are used to reap harvests that are sufficient to feed the world’s largest population and still have surplus for export. An estimated 544,784 square kilometers of land were irrigated in 2004.