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. Temperature differences in winter are great, but in summer the diversity is considerably less.
Precipitation varies regionally even more than temperature.
China south of the Qin Ling 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. Wildlife China lies in two of the world's major zoogeographic regions, the Palearctic and the Oriental.