Since Shenzhen is in the southern part of China, it is quite warm there. Its temperature is from around 15~24C in Dec. For attractions, you can go to the Splendid China, China Folk Culture Villages, Window of the World and Shenzhen Happy Valley. If you have more time, Da Meisha and Xiao Meisha Scenic Area, Meridian View Center and Minsk World are also good choices.