Northern China has wet summers and dry winters. On the northern plain it is colder in winter than anywhere else in the world at the same latitude, and for at least a month the temperature is constantly below freezing. Further south it is warmer and in the valley of the Yangtze River the winter is milder with a little rain. In the far south conditions are hot all year round. June to September are the wettest months when the summer monsoon blowing in from the south and southeast brings much rain.
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 40°C from north to south. Temperatures range from –30°C in the north in January to 28°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.
Monsoon winds, caused by differences in the heat-absorbing capacity of the continent and the ocean, dominate the climate. Alternating seasonal air-mass movements and accompanying winds are moist in summer and dry in winter. There is an alternating wet monsoon in the summer and a dry monsoon in winter. Summer monsoon winds bring warm and wet currents into South China and northward. The advance and retreat of the monsoons account in large degree for the timing of the rainy season and the amount of rainfall throughout the country. North China and southward are affected by the seasonal cold, dry winds from Siberia and the Mongolia Plateau between September/October and March/April. Tremendous differences in latitude, longitude, and altitude give rise to sharp variations in precipitation and temperature within China. Although most of the country lies in the temperate belt, its climatic patterns are complex.
China's northernmost point lies along the Amur River in Heilongjiang province in the cold-temperate zone; its southernmost point, Hainan island province, has a tropical climate. Temperature differences in winter are great, but in summer the diversity is considerably less. For example, the northern portions of Heilongjiang experience an average January mean temperature of below 0°C, and the reading may drop to minus 30°C; the average July mean in the same area may exceed 20°C. By contrast, the central and southern parts of Guangdong Province experience an average January temperature of above 10°C, while the July mean is about 28°C.
Precipitation varies regionally even more than temperature. China south of the Qinling experiences abundant rainfall, most of it coming with the summer monsoons. To the north and west of the range, however, rainfall is uncertain. The farther north and west one moves, the scantier and more uncertain it becomes. The northwest has the lowest annual rainfall in the country and no precipitation at all in its desert areas.
The climate of China is extremely diverse; subtropical in the south to subarctic in the north. Monsoon winds, caused by differences in the heat-absorbing capacity of the continent and the ocean, dominate the climate. Alternating seasonal air-mass movements and accompanying winds are moist in summer and dry in winter. The advance and retreat of the monsoons account in large degree for the timing of the rainy season and the amount of rainfall throughout the country. Tremendous differences in latitude, longitude, and altitude give rise to sharp variations in precipitation and temperature within China. Although most of the country lies in the temperate belt, its climatic patterns are complex.
China's northernmost province Heilongjiang has a subarctic climate; its southernmost point, Hainan Island (an island away from mainland China), has a tropical climate. Temperature differences in winter are great, but in summer the diversity is considerably less. For example, the northern portions of Heilongjiang Province experience an average January mean temperature of below 0°C, and the reading may drop to minus 30°C; the average July mean in the same area may exceed 20 °C. By contrast, the central and southern parts of Guangdong Province experience an average January temperature of above 10 °C, while the July mean is about 28 °C.
Precipitation varies regionally even more than temperature. China south of the Qinling mountains experiences abundant rainfall, most of it coming with the summer monsoons. To the north and west of the range, however, rainfall is uncertain. The farther north and west one moves, the scantier and more uncertain it becomes. The northwest has the lowest annual rainfall in the country and no precipitation at all in its desert areas. China experiences frequent typhoons (about five per year along southern and eastern coasts), damaging floods, monsoons, tsunamis, and droughts.