Jan 13 - 19 2016 great wall

It will be fine to visit the Wall. If you are lucky, it may snow at that time, hence you will have a stunning snow view on the great wall. But it will be very cold, so wear thick warm clothes when going there.

The terracotta warriors are in Xian, where will be warmer than BJ. But still you need to wear winter clothes. And there is no much difference to visit either in winter or summer.