Provincial civil affairs departments said rains and flooding have already caused 13 deaths. One person has also been reported missing since Saturday, Xinhua news agency reported.
Officials said 37,000 houses have been severely damaged or destroyed and 254,000 hectares of crops have been rendered unsuitable for harvest.
Flooding in the Hunan province trapped 16 coal miners underground Wednesday. While water has been pumped out of the mine, rescue operations were still under way as of Thursday afternoon.
A separate national emergency response plan was issued after a mudslide triggered by rains last week in Ningnan county, Szechuan, which killed seven. Thirty-three people were still missing as of Wednesday.