Torrential rain battered southern China leaving cars submerged by severe floods.

Video shows the deluge covering parked cars following an hour of heavy downpour in the Xixiangtang District of Nanning City in the Guangxi Zhuang region on May 19.

The extreme weather has caused urban flooding in multiple districts as a Level III emergency response - the second-highest out of four levels - was raised for heavy rain and flood.

Local media reported that the peak rainfall intensity in Nanning exceeded 100 millimetres in one hour.

Floods have receded in most of the waterlogged areas in the city as of 7:30 pm on May 19.

However, the National Meteorological Center (NMC) forecasted that storms would hit Guangdong, Fujian, Yunnan, Hainan and Guangxi on Monday, May 20.

NMC chief forecaster Zhang Tao said the rains were caused by a strengthening northward movement of the South China Sea monsoon, which was encountering cold and dry winds in the South China and Jiangnan regions.