Heavy rain killed more than 30 people and forced authorities to evacuate tens of thousands as swathes of northern China were lashed by torrential downpours that sparked landslides and flooding, state media said Tuesday.

Weather authorities have issued their second-highest rainstorm warning for the capital Beijing, neighbouring Hebei and Tianjin, as well as 10 other provinces, state news agency Xinhua said.

The rains are expected to last into today.

The heavy rainstorms had left 30 people dead in Beijing as of midnight Monday, Xinhua said, citing flood control authorities.

More than 80,000 people have been evacuated in the capital alone, according to state-run Beijing Daily.

The death toll was highest in Miyun, a northeastern suburb, it said.

"This time the rain was unusually heavy, it's not normally like this," a Miyun resident said as water streamed down the road outside her house.

"The road is full of water so people aren't going to work," she said.

In Xinanzhuang village, murky water had submerged homes, cars and a road.

A local man in his sixties said he had never seen water levels so high.

Nearby, torrents of water gushed from spillways in the Miyun Reservoir, which authorities said reached its highest levels since its construction in 1959.

Beijing's northern Huairou district and southwestern Fangshan were also badly affected, state media said.

Dozens of roads have been closed and over 130 villages have lost electricity, Beijing Daily said.

"Please pay attention to weather forecasts and warnings and do not go to risk areas unless necessary," the outlet said.

More than 10,000 people also evacuated their homes in the neighbouring port city of Tianjin, which saw major flash floods, according to state-owned nationalist tabloid Global Times.