A landslide blocks Yiu Hing Road near Yiu Tung Estate in Shau Kei Wan due to a downpour, on Sept 8, 2023. (CALVIN NG / CHINA DAILY)

A “once-in-a-century” rainstorm inundated and flooded Guangdong province and Hong Kong from Thursday night through Friday, submerging roads, tunnels, and metro stations, as well as cars and buildings, with over 100 people injured and thousands stranded.

The rainstorm had gradually eased by noon on Friday as local authorities made an all-out effort to aid flood-hit residents, clear flooded roads, and resume the flow of disrupted traffic.

The torrential rains were brought in by a trough of low pressure associated with the remnants of Haikui — a typhoon that hit the region earlier this week.

The Hong Kong Observatory said it recorded more than 600 millimeters of rainfall in 24 hours, amounting to a quarter of the city’s annual precipitation.

Between 11 pm and midnight on Thursday, the city logged an hourly rainfall of 158.1 mm — the highest level since 1884, when record-keeping started 

Between 11 pm and midnight on Thursday, the city logged an hourly rainfall of 158.1 mm — the highest level since 1884, when record-keeping started. The city issued a blackrainstorm warning signal at 11:05 pm on Thursday, which lasted for 16 hours and 35 minutes, breaking the previous record of five hours and 47 minutes on Aug 23, 1999.

Meanwhile, in Chai Wan, Wong Tai Sin, Sheung Shui and many other areas across the city, raging floods deluged streets, shopping malls, underground parking lots and metro stations. Videos showing alarming flood-related scenes, including a woman swept away by floodwaters in a street, went viral online.

Some residents said they experienced “moments of helplessness” during the devastating weather and traffic standstills.

READ MORE: Rainstorm disrupts daily life in Hong Kong

Photographer Leung Cheuk-hei spent a sleepless night sheltering in a small restaurant in Shenzhen. After attending a banquet in Shenzhen on Thursday night, he found himself caught in the intense rain without a way to return to Hong Kong, and nearby hotels were unable to check customers in because of power outages.

After finally entering Hong Kong through the Lo Wu Control Point on Friday, Leung said, he had to navigate his way using multiple metro and bus connections because parts of the city’s transportation network were shuttered after the storm.

Meanwhile, Wang Tianzi was trapped in Tsim Sha Tsui all night by the unexpected rain after dining out on Thursday night. The exhausted securities practitioner eventually was able to hail a car on Uber and return to his home in Sheung Wan at about 5 am on Friday.

Hong Kong Polytechnic University student Lu Hongjing said she had to alter her plans to travel to Shenzhen for a vaccination because of the severe weather conditions.

Residents evacuate on a rubber dinghy through a flooded street in Panyu district, Guangzhou, Guangdong province, Sept 8, 2023. (PARKER ZHENG / CHINA DAILY)

‘Extreme conditions’

As the heavy rain continued, the Hong Kong Special Administrative Region government announced on Friday morning that the city was facing “extreme conditions” in which events and activities would be suspended. School classes and the trading service of the Hong Kong Stock Exchange were consequently suspended on Friday.

A total of 132 people were admitted to public hospitals, with four in serious condition, according to the Hospital Authority

By noon on Friday, authorities had evacuated 110 residents and aided 20 injured people during the rainstorm. The police and fire services had received over 1,000 calls for assistance and handled 341 cases of flooding, 10 related to landslides, 58 for people trapped in elevators and 18 related to fallen trees.

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A total of 132 people were admitted to public hospitals, with four in serious condition, according to the Hospital Authority.

Hong Kong Chief Executive John Lee Ka-chiu visited a community center in Tsz Wan Shan, the Wong Tai Sin district, and the Yiu Tung Estate in Shau Kei Wan on Friday afternoon to learn about the situations there. Both places had been severely hit by the rainstorm.

Lee also said in a social media post that he had instructed all government departments to continue to do their utmost to assist local residents.

As the storm eased, Hong Kong’s metro and bus operators have gradually resumed services since Friday morning.

The government said the “extreme conditions” would be maintained at least through the end of Friday and would end once public transportation returns to normal, Chief Secretary for Administration Eric Chan Kwok-ki told a cross-department news conference on Friday afternoon.

The torrential rain also wreaked havoc in many cities in Guangdong. In the 24 hours before 7 am on Friday, about 100 townships and subdistricts in Guangdong were hit by over 250 mm of rainfall.

Classes at primary and middle schools in Shenzhen, Zhuhai and parts of Guangzhou, Dongguan and Foshan were suspended on Friday, while some roads and highways in the province were temporarily closed because of the risk of landslides, flooding or fallen trees.

As of noon on Friday, the province had received 805 reports of heavy rainfall-related alerts, and had evacuated and rescued 3,432 people.

In Shenzhen, about 100 people who had been stranded at the Shenzhen Railway Station in Luohu district were rescued on Friday morning, after the station was deluged by the heavy rainfall

In Shenzhen, about 100 people who had been stranded at the Shenzhen Railway Station in Luohu district were rescued on Friday morning, after the station was deluged by the heavy rainfall.

Shenzhen also temporarily closed the Liantang and Wenjindu land boundary control points, with waist-high water inundating the ground floor leading to the arrival hall at the height of the storm in the wake of the heavy rain. It is unknown when the ports will resume service.

READ MORE: Guangdong ups emergency response for heavy flood

Faced with the record-breaking rains, Shenzhen had to discharge water from the Shenzhen Reservoir on Thursday night, as its water level had approached the flood limit. Although the water project is located on the Shenzhen-Hong Kong border, the discharge eventually had a limited impact on people on both sides.

The Shenzhen government also launched a temporary assistance program to help residents who have encountered difficulties in their basic living conditions because of the rainstorm.

Eligible residents can receive a one-time payment amounting to not less than two months of the city’s minimum living guarantee standard — 2,826 yuan ($385) — and not exceeding three months of the minimum living guarantee of 4,239 yuan.

As the storm moved westward, the Macao Special Administrative Region issued its red rainstorm warning — the mid-level in its three-level system — twice, at 4:25 am and 11:40 am. Also on Friday, the Macao Peninsula had logged over 160 mm of precipitation as of 6 pm, with sporadic flooding and landslides reported in the city’s Coloane district.

Contact the writers at williamxu@chinadailyhk.com