China's meteorological authority on Sunday maintained a blue alert, the lowest level, for rainstorms in southern parts of the country.
On Sunday and Monday, 100 to 150 mm of rain will fall in parts of Jiangxi, Guangxi and Guangdong, the National Meteorological Center said.
Hunan and Fujian will also experience heavy rain, according to the center.
It advised people in those areas to take precautions against possible waterlogging and floods.
China has a four-tier color-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.