_Climate._--The climate over so vast an area as China necessarily varies greatly. The southern parts of Yun-nan, Kwang-si and Kwang-tung (including the city of Canton) lie within the tropics. The northern zone (in which lies Peking) by contrast has a climate which resembles that of northern Europe, with winters of Arctic severity. The central zone (in which Shanghai is situated) has a generally temperate climate. But over both northern and central China the influence of the great plateau of Mongolia tends to establish uniform conditions unusual in so large an area. The prevailing winds during summer--the rainy season--are south-easterly, caused by heat and the ascending current of air over the sandy deserts of central Asia, thus drawing in a current from the Pacific Ocean. In the winter the converse takes place, and the prevailing winds, descending from the Mongolian plateau, are north and north-west, and are cold and dry. From October to May the climate of central China is bracing and enjoyable. The rainfall is moderate and regular.
In northern China the inequalities both of temperature and rainfall are greater than in the central provinces. In the province of Chih-li, for example, the heat of summer is as intense as is the cold of winter. In summer the rains often render the plain swampy, while the dry persistent westerly winds of spring create dust storms (experienced in Peking from March to June). The rainfall is, however, uncertain, and thus the harvests are precarious. The provinces of Shan-tung and Shan-si are peculiarly liable to prolonged periods of drought, with consequent severe famines such as that of 1877-1878, when many millions died. In these regions the air is generally extremely dry, and the daily variations of temperature consequent on excessive radiation are much greater than farther south.
Accurate statistics both of heat and rainfall are available from a few stations only. The rainfall on the southern coasts is said to be about 100 in. yearly; at Peking the rainfall is about 24 in. a year. In the coast regions the temperatures of Peking, Shanghai and Canton may be taken as typical of those of the northern, central and southern zones. In Peking (39° N.) the mean annual temperature is about 53° F., the mean for January 23°, for July 79°. In Shanghai (31° 11' N.)[7] the mean annual temperature is 59°, the mean for January 36.2°, for July 80.4°. In Canton (23° 15' N.) the mean annual temperature is 70°, the mean for January 54°, for July 82°. The range of temperature, even within the tropics, is noteworthy. At Peking and Tientsin the thermometer in winter falls sometimes to 5° below zero and rises in summer to 105° (at Taku 107° has been recorded); in Shanghai in winter the thermometer falls to 18° and in summer rises to 102°. In Canton frost is said to have been recorded, but according to the _China Sea Directory_ the extreme range is from 38° to 100°.[8] The climate of Shanghai, which resembles, but is not so good as, that of the Yangtsze-kiang valley generally, is fairly healthy, but there is an almost constant excess of moisture. The summer months, July to September, are very hot, while snow usually falls in December and January.