Beijing and other cities are braced for severe flooding as summer storms roll across many parts of China, while inland regions bake in intense heat, threatening to shrink the country’s biggest freshwater lake.

Wild weather swings have gripped China since April, causing deaths, damaging infrastructure and wilting crops as well as raising fears about its ability to cope with climate change.

China historically enters its peak rainy season in late July but extreme weather has made storms more intense and unpredictable, exposing heavily built-up megacities with poor or insufficient drainage to potentially deadly floods.

In Beijing, authorities this week deployed more than 2600 people to drain dozens of pumping stations in advance and clear thousands of water drainage outlets along roads.

Several bus routes plying the suburbs and mountainous areas were halted.

Authorities in the neighbouring city of Tianjin also ramped up flood control efforts in the Hai basin, a major northern drainage system.

By contrast, scant rainfall in Jiangxi province has resulted in Poyang Lake, the country’s largest body of fresh water, ebbing to its lowest level for this time of the year since records began in 1951.

Poyang Lake, known as the kidneys of China due to the role it plays in regulating the flow of the Yangtze River, normally swells in summer due to rain and retreats in winter.

Last year, it also unexpectedly shrank due to drought.

Temperatures of 35 degrees Celsius and above continued to menace other parts of China.

Northwestern Xinjiang, where temperatures hit a record high 52.2C on Sunday, remained blanketed in worse-than-usual heat while in neighbouring Gansu province, some areas suffered intense heat as others warned of floods and landslides.

Officials have warned repeatedly that China is vulnerable to the impact of climate change due to its large population and unevenly distributed water supplies.

In Jiangsu province, a waterfall tumbled into a high-speed railway station in the rain-drenched city of Wuxi, according to social media clips.

As many as 150 cities are waterlogged each summer, despite efforts to improve drainage.

In July 2021, extreme rain in the city of Zhengzhou, in Henan province, killed almost 400 people, including 14 who drowned in a submerged subway line.

More rain had fallen across three days than what the city gets in a year.

Heavy rainfall of up to 130mm is expected in parts of Hebei, Beijing and Tianjin until Saturday morning, the national weather bureau warned.

On Friday morning, part of an ancient city wall in Chongqing in southwestern China collapsed after hourly rainfall of up to 100.3mm in the past day.

-AAP