Floods across large swathes of central and eastern China that have left more than 140 people dead or missing are hitting record levels, with authorities warning the worst was yet to come.

The coronavirus ground zero of Wuhan, through which the powerful Yangtze River winds, is on an expanding list of areas warily watching the rising waters, with the river hitting its third-highest levels in history in the city of 11 million and projected to increase through the week, according to state-controlled media. Summer flooding has been an annual scourge in China since ancient times, often focused along the vast Yangtze basin that drains much of the central part of the country.

Steady rains since late June have flooded huge areas, leaving 141 people dead or missing so far, affecting 37.89 million others and destroying 28,000 homes, according to central government tallies. But worsening downpours since last week have caused water levels to spike higher and the government to ramp up alert levels.

Thirty-three rivers have reached record highs, while alerts have been issued on a total of 433 rivers, officials from the Ministry of Water Resources said during a briefing in Beijing on Monday. Video broadcast by Chinese state-run media at the weekend showed vast stretches of cities and towns inundated by water that rose in some places to the roofs of single-story homes, as rescue personnel evacuated men, women and children aboard inflatable boats.

Elsewhere, homes were shown flattened by landslides that had tumbled from water-logged hillsides. The worst-hit provinces were Jiangxi, Hubei and Hunan in central China, Anhui, Zhejiang and Jiangsu in the country's east, and the southwestern mega-city of Chongqing, authorities said.

Illustrating the growing alarm, President Xi Jinping on Sunday called on authorities in affected areas to mobilise to help stricken residents, urging them to be "courageous". China's worst floods in recent decades came in 1998 during an El Nino weather effect, killing more than 4,000 people, mostly around the Yangtze.