The national observatory renewed a blue alert, the lowest in its four-tier warning system, on Saturday for rainstorms in south China over the coming two days.
On Saturday, heavy rain is expected in parts of Anhui, Jiangsu, Jiangxi, Zhejiang, Fujian, Hunan, Yunnan, and Guizhou provinces, the National Meteorological Center (NMC) announced.
Some areas of Anhui, Jiangxi and Guizhou will see torrential rain accompanied by thunder or hail, according to the NMC.
On Sunday, the rain will get heavier in these regions.
The NMC issued a blue alert for rain on Friday before this renewal.
The public have been told to reduce outdoor activities and prepare for possible floods and landslides, said the NMC.
China has a four-tier color-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.
