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 deg. N.) the mean annual temperature is about 53 deg. F.,
the mean for January 23 deg., for July 79 deg. In Shanghai (31 deg. 11'
N.)[7] the mean annual temperature is 59 deg., the mean for January 36.2
deg., for July 80.4 deg. In Canton (23 deg. 1