Low temperatures and torrential rains in South China have killed at least 86 people and affected 8 million others, with downpours forecast to continue in the next few days.

Sixteen people have also gone missing and 275,000 others evacuated in 10 provinces and municipalities in the south since heavy rain hit the areas on May 5, Jiao Yong, vice-minister of water resources, said over the weekend.

"This is meteorologically unusual," China News Services quoted Jiao as saying.

The flood season will be made worse by concentrated, frequent rain in some areas, he said.

The China Meteorological Administration (CMA) forecast on Sunday that most parts of South China will see more wet weather with heavy rainfall or storms in the next three days.

Hubei and Guizhou provinces as well as Chongqing municipality can expect heavy rain or storms during the period, while torrential rain is forecast to hit some southern areas, the CMA said.

A cold front moving eastward is also set to bring temperature plunges and strong winds in northwest China during the coming three days. Temperatures in Gansu province and the Inner Mongolia autonomous region are forecast to fall by up to 8 C. Inner Mongolia and the Xinjiang Uygur autonomous region will also be affected by dust storms.

Rainstorms in South China since early May have triggered floods and mudslides as well as swollen rivers, burst dikes, threatened reservoirs and damaged highways, bridges and power facilities.

Floods triggered by heavy rains on May 12 and 13 broke four bridges in Xupu county in Hunan province.

More than 8,000 people in Shanxi township of Xupu have become isolated and people can only carry relief materials through a chain bridge.

Water resources, power supply and telecommunications facilities in Shanxi township were also seriously damaged. Rice supplies barely escaped the floods, with rice and edible oil stocks running out.

Emergency workers have already set up a temporary road linking the county to the outside on Saturday.

Still, water under an overpass around the railway station in Xinyu city in Jiangxi province has accumulated to 6 m high in the rainstorm starting on Wednesday.

No rainfall and flooding of this magnitude have been recorded since 1984, the local government said.

Three rounds of heavy rain since May 7 have also brought 440 mm of rainfall, or more than 25 percent of the total rainfall in a normal year, to Guangzhou, capital of Guangdong province.

Floods were reported at 99 spots in Guangzhou after a storm on late Friday night, with water up to 30 cm high on some roads. More than 1,180 people were reportedly relocated.

More than 18,000 claims have been made to insurance companies for cars damaged by floods since May 7 in Guangdong.

Service on a section of the subway line No 2 of Guangzhou was also suspended for six hours on Saturday morning after a tunnel beside a station was flooded. Authorities provided free shuttle bus services for affected passengers.

Similarly, the inclement weather delayed at least 57 flights at the city's Baiyun international airport on Friday night.

A total of 2,798 people and 916 pieces of equipment were deployed to fight the latest round of floods in Guangzhou, authorities said.

The worsening extreme weather is partly due to global warming, said Lin Liangxun, chief forecaster with Guangdong Meteorological Center.

Emissions of greenhouse gas emissions have helped reduce the frequency of mid-level rains and caused more storms, he said.