I want to tour China - Shangai, Beijing, Guilin, Hong Kong and Macau in mid-January 2017.

Well, according to the previous statistics, the temperature in Beijing would be quite cold, averagely between 15~30F. Make sure you take down jackets, thick sweaters, boots and scarves.
Shanghai and Guilin would be warmer with the temperature around 40~50F at that time. However, you still need to take thick clothes to keep warm.
The average temperature of HK usually between 55~65F. Coat, jacket and sweater would be enough for you to prepare.