Hi. We want to go to Beijing,Guilin and Sichuan during December. is it freezing? do you recommend?

Ohad, it's cold in Beijing during December. You should take warm clothes including down jacket, overcoat, sweater and warm clothes. Lakes in Beijing are frozen. It's warmer in Guilin. The river and lakes are not frozen because the temperature is from 7 to 15 degrees Celsius. However, the water level isn't high. You didn't say where you would go to visit in Sichuan. So I am not able to provide much more information.