Hong Kong experienced extreme rainfall on Friday, resulting in widespread flooding across the densely populated city.

Streets, shopping malls, and metro stations were submerged in water, leading authorities to close schools and advise workers to stay home.

This Chinese special administrative region witnessed the highest hourly rainfall ever recorded in its 140-year history, causing cascades of water to flow down its mountainous terrain.

Authorities issued warnings of potential landslides due to the heavy rain.

Videos circulated on social media depicted streets transformed into torrents, and one clip showed metro workers wading through waist-deep water in a station, attempting to manage the flow of water pouring down from street level.

The city’s crucial cross-harbour tunnel, connecting Hong Kong Island to Kowloon, also faced significant flooding. Images revealed a waterlogged shopping centre in the Chai Wan district.

Between 11 p.m. HKT on Thursday and midnight on Friday (1500 to 1600 GMT on Thursday), the Hong Kong Observatory reported a rainfall of 158.1 millimetres (6.2 inches).

The weather bureau issued the highest-level “black” rainstorm warning and recorded over 200 mm of rainfall in various parts of Hong Kong since Thursday night.

The extreme weather conditions resulted from the remnants of Typhoon Haikui and the associated low-pressure system, which brought heavy rain to China’s Guangdong coast since Thursday.

The adverse weather was expected to persist until at least noon on Friday, leading to the closure of Hong Kong’s stock exchange for the morning session.

If the “black” rainstorm warning remains in effect by noon, the exchange will remain closed for the afternoon session as well.

Hong Kong’s leader, John Lee, expressed deep concern over the extensive flooding and instructed all departments to respond with “all-out efforts” to address the situation.

Additionally, some passenger and cargo clearance points at two border control points between Hong Kong and the neighbouring city of Shenzhen were suspended due to flooding, as reported by the government.

In the Wong Tai Sin district, vehicles struggled to navigate a major road submerged in water.

Hong Kong’s MTR Corp, responsible for the city’s rail network, announced the closure of at least one rail line, with others operating on delayed schedules due to the adverse weather conditions.