China's climate is too varied for any but the vaguest
generalizations: summers in most parts of the country are extremely
hot and humid, which can make travel even harder work than usual,
and winters are generally bitterly cold.
The south , however, is subtropical, with wet, humid
summers (April to September), when temperatures can approach 40°C,
and a typhoon season on the southeast coast between July and
September. Though it is often still hot enough to swim in the sea
in December, the short winters, from January to March, can be
surprisingly chilly.
Central China , around Shanghai and the Yangzi River, has
brief, cold winters, with temperatures dipping below zero, and
long, hot, humid summers. It is not without reason that China's
three "furnaces" - Chongqing, Wuhan and Nanjing - are all in the
Yangzi basin. Rainfall here is high all year round. Farther north,
the Yellow River basin marks a rough boundary in Chinese heating
habits, with central heating fitted as standard in buildings north
of here, helping to make northern China's harsh winters a little
more tolerable. Winter temperatures in Beijing rarely rise
above zero from December to March, and freezing winds off the
Mongolian plains add a vicious windchill factor. In summer,
however, temperatures can be well over 30°C. In the far
north , Inner Mongolia and Manchuria, winters are at least
clear and dry, but temperatures remain way below zero, while
summers can be uncomfortably warm. The Northwest gets
fiercely hot in summer, but without the humidity of the rest of the
country, and winters are as bitter as anywhere else in northern
China. Tibet is ideal in mid-summer, when its mountain
plateaux are pleasantly warm and dry. June to September are the
wettest months with winter temperatures in Lhasa frequently falling
below freezing.
Overall, the best time to visit China is spring or
autumn , when the weather is at its most temperate. In the
spring, it's best to start in the south and work north or west as
summer approaches; in the autumn, start in the north and work
south. If you can brave the cold, winters are considerably
enlivened by the preparations for Chinese New Year; but during New
Year itself, travelling can be extremely difficult as offices close
and much of the population is on the move.