Owing to the sheer size of China, the climate varies a huge amount. North-easterly regions see hot, dry summers and freezing winters, the south east tends to be very hot and wet all year round, central regions see four seasons that include hot summers, cold winters and rain all year round, the coastal regions are humid, experiencing monsoons at some points. Average temperatures obviously vary a great deal, for example: Beijing sees summer highs in July of around 31 degrees and winter lows hitting around 1 degree, whereas Shanghai sees summer highs of 32 degrees in July and winter lows of around 8 degrees.

For current forecasts:

http://www.weathercity.com/cn/beijing/