Hiking in late Jan. 2013 of Huashan over 2 days

It is open at that time, so do not worry about it.
Hotels on mountains and the transportation are still in operation.
It is hard to tell you the exact temperature at that time. It will be cold at base and no matter what kind of temperature is on the peak, you need to take down coat. The wind is heavy at that time. The temperature difference is not very big in winter comparing with that in summer time.