Downtown Beijing in the rain on Sunday evening as seen from within a taxi Photo: Courtesy of Ah Bu

Beijing has closed multiple tourist sites and issued emergency safety warnings for residents as the capital city is about to see 2021's heaviest rainfall, according to the weather forecast, starting from Sunday afternoon, and the rain could last for 30 hours. Experts sought to ease public concerns, saying that the rainfall comes within expectations amid the city's flood season. 

The Beijing Meteorological Service issued an early yellow warning signal for rainstorm on Sunday morning. Cumulative rainfall is expected to reach 60 to 100 millimeters in the city from Sunday evening to Tuesday morning, with 7 to 9 gale-force winds.

The rainfall will be concentrated from 2 am on Monday to 2 am on Tuesday. The whole process might take more than 30 hours.

Rain of such intensity, though relatively higher than in recent years, is within expectations in Beijing's flood season of July and August, during which nearly 70 percent of the city's annual rain falls, Zhang Mingying, a Beijing-based meteorologist, told the Global Times on Sunday. 

He noted that the precipitation formed after warm and moist air flowed along the edge of the Pacific high pressure weather system from South China to North China.

As of press time, 494 flights at Beijing Capital International Airport and Beijing Daxing International  Airport have been canceled due to the rain warning. 

To cope with the potential drainage challenges, Beijing Drainage Group has assigned more than 2,900 staff members to pump stations and water plants. Eleven reclaimed water plants will have a capacity of 400,000 cubic meters for the pipeline system in Beijing.

Beijing's primary and secondary schools and kindergartens will be closed on Monday, and all outdoor sports, cultural and commercial activities will be suspended from Sunday night. 

The Beijing hydrology station issued a yellow alert for floods with the flow rate of some rivers predicted to be 1,000 cubic meters per second.

The capital city's western, northern and southwestern regions will be most affected by the rain, with cumulative rainfall expected to reach 100 to 150 millimeters. At some specific places, the number will soar to 200 to 300 millimeters, according to the forecast. 

The maximum hourly rainfall might be 30 to 60 millimeters, reaching 100 millimeters locally. The wind can be 11 gale-force locally. 

Authorities of northwest Beijing's Yanqing and Changping districts said that they would close all scenic spots and suspend all rural homestays in Sunday afternoon due to the risks of floods, mountain torrents and other dangers. The Beijing Botanical Garden, the Xiangshan Park and the Juyong Pass of the Great Wall are among other scenic spots to be closed for tourists. 

The China Meteorological Administration launched a IV-level emergency response on Sunday as regions in North China and north of the Yellow River and Huai River anticipate heavy rains.