China's meteorological authority on Saturday issued a blue alert, the lowest level in a four-tier warning system, for heavy rain in some eastern and southern regions.
From Saturday to Sunday, heavy rain is expected in a vast part between the Yellow River and the Huaihe River, as well as parts of Hainan and Guangdong provinces, the National Meteorological Center said.
Provinces of Anhui, Shandong, Jiangsu and Hainan may see torrential rain of up to 140 mm in 24 hours.
The center cautioned that local governments should take measures against storms, cut off outdoor power supplies in dangerous regions and prevent potential disasters, including mountain floods and landslides.
China has a four-tier color-coded weather warning system for heavy rain, with red representing the most severe, followed by orange, yellow and blue.