What is the weather going to be like on the Mutianyu Great Wall on Friday/tomorrow?

Adrienne, it will be very cold. The temperature will be 3 to 21°F (-7 to -18 Celsius Degrees). If you go there, please wear warm clothes like down jacket, scarf, hat and gloves. It might be icy on the wall. You should climb carefully. It would be better if you wore antiskid shoes.