Does all Zhangjiajie scenic sites will open in february from 11 to 13? how will be february?

The Tianmen Mountain will be closed by then and the reopening time is unknown. Other scenic spots will be normally open, and some parts may be temporarily closed due to possible heavy snow.

It can be cold during that time, with most cloudy days and some snowfall. Personally, it is worth to go in winter, especially when there is some snowfall with better views. 2-3 days are recommended there so that you can cover all major spots.