Further rain has been forecast until the weekend in China’s Henan province where at least 25 people have been killed in days of flooding.
From Saturday to Tuesday, 3,535 weather stations in Henan saw rainfall exceeding 5cm, of which 1,614 had levels above 10cm and 151 above 25cm.
Twelve people died and more than 500 were pulled to safety after a subway tunnel flooded in the Zhengzhou, with images and video posted on social media showing commuters immersed in chest-deep waters in the dark.
“I was really scared, but the most terrifying thing was not the water, but the diminishing air supply in the carriage,” one person wrote.
Around 100,000 people have been evacuated after dams and reservoirs swelled to critical levels.
The three days of rain matched a level seen only “once in a thousand years“, the Zhengzhou weather bureau said.
The torrential downpours halted bus services in the city of 12 million people about 650 km (400 miles) southwest of China‘s capital Beijing.
And schools and hospitals were marooned and people caught in the floods flocked to shelter in libraries, cinemas and museums.
“We’ve up to 200 people of all ages seeking temporary shelter,” said staff member at the Zhengzhou Science and Technology Museum.
The People’s Liberation Army has sent more than 5,700 soldiers and personnel to help with search and rescue.
Like recent heatwaves in the United States and Canada and extreme flooding seen in western Europe, the rainfall in China was almost certainly linked to global warming, scientists have claimed.
“Such extreme weather events will likely become more frequent in the future,” said Johnny Chan, a professor of atmospheric science at City University of Hong Kong.
“What is needed is for governments to develop strategies to adapt to such changes,” he added, referring to authorities at city, province and national levels.”
President Xi Jinping said in a statement broadcast by state television: “Flood prevention efforts have become very difficult.”