I will be visiting Shanghai, Hangzhou, Huangshan, SuZhou from 8th Feb - 16 febth, 2013.

The weather is not bad during that time for these places, but I suggest you to take a down jacket if you want to go to Huangshan. It will be cold on the mountain.
In other places, you still need to prepare a thick coat and a sweater.
There is one point I should remind you is that some attraction on the mountain may be closed during that time.