The massive rainfall that has swamped the Chinese capital Beijing over the last week was the heaviest since records began 140 years ago, the local weather service confirmed Wednesday.

Millions of people have been hit by extreme weather events and prolonged heatwaves around the globe in recent weeks, events that scientists say are being exacerbated by climate change.

And the Beijing Meteorological Service said the capital has just experienced the "heaviest rainfall in 140 years," when city authorities started keeping records.

"The maximum (amount) of rainfall recorded during this storm, which was 744.8 millimeters, occurred at the Wangjiayuan Reservoir in Changping," the service said, adding the largest volume previously recorded was 609 millimeters in 1891.

At least 20 people have died in the rains in Beijing, the Associated Press reported Tuesday, with more than a dozen missing.

The epicenter of flooding shifted to neighboring Hebei province Wednesday.

In Beijing's Fangshan district – on the border between the capital and Hebei – an Agence France-Presse (AFP) team saw a park that had been completely flooded, with tons of rubbish that had been washed away by torrential rains stuck near a bridge.

The area had been "extremely dangerous" on Tuesday, a police officer said.

Journalists also saw a military vehicle with caterpillar wheels on its way back from the most affected areas.

And in the opposite direction, AFP saw an ambulance, a rescue boat and a police car heading to Zhuozhou, a hard-hit district of Hebei.

State media footage showed rescuers rowing inflatable rafts through waterlogged neighborhoods, while locals clung to construction scaffolding awaiting help.

Storm Doksuri, a former super typhoon, swept northward over China after hitting the southern Fujian province last week, following its battering of the Philippines.

Heavy rains began pounding the typically dry capital and surrounding areas Saturday.

The amount recorded in just 40 hours neared the average rainfall for the entire month of July.

State media warned last week that 130 million people would be affected by the extremely heavy rainfall across northern China.

Swaths of suburban Beijing and the surrounding areas have been inundated, with state media reporting 974,400 people have been evacuated in the capital and neighboring Hebei province.

A further 42,211 people have been evacuated in Shanxi province to the west.

Authorities in the capital lifted the red alert for flooding Wednesday morning "as the water flow in major rivers has gone below the warning mark," state news agency Xinhua said.

'Extreme weather'

China has been hit hard by extreme weather in recent months, from record-breaking heatwaves to deadly rain.

Ma Jun, director of the Beijing-based NGO the Institute of Public and Environmental Affairs, said that while the typhoon had brought rain, rising ocean temperatures caused by climate change were also causing extreme weather.

"China has suffered unprecedented extreme heatwaves since last year ... this year, there are record-breaking high temperatures in Northern China," Ma told AFP.

"These heatwaves are linked to global warming, and this is what most climate scientists around the world tend to agree," he said.

With rainfall easing, the focus has moved to the relief operation, with hundreds of rescue workers from the Chinese Red Cross being sent to hard-hit areas to clean up debris and help evacuate victims, Xinhua said.

Two of the 11 people killed in the rains in Beijing died while "on duty during rescue and relief," according to state broadcaster CCTV.

Thirteen people were still missing but another 14 have been found safe, the broadcaster said.

In neighboring Hebei province, nine people were killed and six were missing, it said.

Another two casualties were reported in northeastern Liaoning province at the weekend.

President Xi Jinping called Tuesday for "every effort" to rescue those "lost or trapped" by the storm.

And visiting a relief work site in Beijing's Mentougou – one of the capital's hardest-hit areas – Vice-Premier Zhang Guoqing urged "all-out" efforts to rescue those still missing.

"The top priority of the current work is to save people's lives, race against the time to search for the people missing or trapped and minimize casualties," Zhang said, according to Xinhua.

The country is now on alert for the arrival of Typhoon Khanun, the sixth such storm of the year, as it nears China's east coast.