What is the temperature like in December? I plan to go to Guilin 29/12/2014-2/1/2015.

During your travel, the temp shall range from 6℃ to 18℃ based on the previous records. You can take along sweater and downjacket, not very thick type. It would generally be cloudy or sunny then. Though, check ahead the weather forecast in case there is sudden rainfall, which would not be heavy!