Beijing is becoming very cold in Mid-November. It may be around zero or below zero degree in the morning and at night. I think you need to wear swearter and warm coat, ot even thin downcoat. Xian is a little better. Sweater and coat is enough. The average temperature of Xian in this month is about 6.5 degrees. Shanghai is a bit warmer than Xian, still need to bring sweater and overcoat. We has snow in Mid-November last year. Hong Kong weather is much more mild. The temperature is about 10-20 degrees at daytime.