Think "Northern China" and the Great Wall immediately comes to mind. But Northern China is much more than just Beijing and the Great Wall. You've got all of that area we used to call "Manchuria" – or Heilongjiang, Jilin and Liaoning Provinces. You've got Inner Mongolia as well as Hebei and Shanxi Provinces. There's much to do and see and you could probably spend your whole trip up there in the far reaches scouting for Siberian Tigers
and maybe doing a little skiing
But what's the weather like? That's an excellent question. It is different than much of the rest of China. You won't be quite so hot and humid and you'll experience a longer winter. But that's OK too, because there are plenty of winter activities in China.
Read a full profile of Northern China Weather.
You can also refer to the About.com Geography site's China Maps section for more information about Northern China.