By Xin Dingding， Zheng Jinran and Peng Yining
Police and airport take measures as clean-up continues.
Beijing was preparing for further downpours on Wednesday after the heaviest rainfall for 61 years on Saturday lashed the city and left 37 people dead.
Heavy rain is forecast for the capital over the coming days, with average precipitation of 30 to 50 millimeters, Zhang Linna, chief forecaster at the Beijing Meteorological Station, said.
Workers were allowed to go home early on Wednesday to avoid evening traffic jams.
The capital's roads will be cordoned off if water rises above 30 centimeters, and traffic police were dispatched to deal with emergencies, traffic authorities said.
Beijing Capital International Airport, with 1,511 flights scheduled for Wednesday, prepared food, water and blankets in case flight delays stranded passengers.
Some passengers went to the trouble of preparing their own food and bringing ample water supplies.
Saturday's torrential rains directly affected 1.6 million people and caused losses of 11.64 billion yuan ($1.82 billion), the Beijing municipal government said on Wednesday night.
In Fangshan, a Beijing district heavily battered by the storm on Saturday, villagers were still trying to clear up.
Hundreds of volunteers in the district's Nanguan village were removing dead pigs and debris.
Many of the dead animals came from a farm with 3,200 pigs that was submerged in water 3 meters deep on Saturday. About 2,900 pigs were killed. The surviving pigs were transferred to another farm. The remains of more than 1,000 dead pigs have been destroyed.
The pig farm was still submerged on Wednesday and a putrid smell lingered in the air.
More than 1,000 carcasses have still to be destroyed, said Qin Xiaogang from the China International Search and Rescue Team.
Heavy rain is likely to trigger mudslides, cave-ins and landslips in mountainous areas.
Villagers in areas that may be threatened took precautions and moved into temporary shelters.
"My mother's house has been leaking since Saturday. The village committee broadcast there will be more rain, and I just cannot let her stay in her house alone any longer," said Yang Qingli, 52, a villager from the district's Beicheying village.
Yang took shelter in a tent in the grounds of a primary school on Sunday and persuaded her 76-year-old mother to join her on Wednesday.
By Wednesday, more than 80 villagers had moved into 30 tents.
"If it rains again, we will move into the school building," she said.
Volunteers also went to Fangshan district to help with local disaster relief work.
Beijing restaurant owner Han Guocheng organized 35 of his employees to go to Beicheying village and help clean up.
Liu Wenxin, 28, who owns a grocery store in Beijing, drove to the village with four friends on Wednesday, and donated bottled water.
"I had wanted to join rescue work for the quakes in Wenchuan in Sichuan province and Yushu Tibetan autonomous prefecture in Qinghai province before, but they were too far away. There is nothing that can stop me from offering my services now," Liu said.
Water supplies in Beicheying village have been cut off since Saturday, and villagers have no water to cook or wash in.
"The air reeks of the smell of dead rats and chickens," Liu Cunli, 50, from Beicheying village, said.
"We have no water to drink or wash in. We urgently need the government to send specialists to prevent an epidemic."
Zhang forecast more heavy rain on Friday and Saturday.
Storms have lashed many parts of China over the last few days. Torrential rain swept through 17 provincial areas on Friday, leaving 95 people dead and another 45 missing, according to the Ministry of Civil Affairs.
The Office of State Flood Control and Drought Relief Headquarters said that, by 2 pm on Wednesday, floods in the upper reaches of the Yangtze River had receded and water levels dropped below the alert level.
In Chongqing, water is receding in most areas after the city's worst flood for 31 years on Tuesday.
In North China's Hebei province, the death toll climbed to 31 after rainstorms hit the province over the weekend, provincial authorities said on Wednesday. At least 20 people were still missing.