In the evening of 7 September 2023, a heavy rainstorm struck the territory of Hong Kong and the Pearl River Delta area, including parts of Guangdong, China and Macau.

[4][5] On 5 September 2023, Typhoon Haikui made landfall in China's Fujian province, subsequently moving into Guangdong, before its remnants stalled over the Pearl River Delta for over two days.

As the low pressure trough associated with Haikui's remnants interacted with the south-westerly monsoon,[6] the Pearl River Delta started experiencing extreme rainfall beginning on the night of 7 September.

[14][15] Luxury houses in Redhill Peninsula near Tai Tam Bay were also exposed with illegal structures following the soil slip.

[16][17] Ruptures of underground water pipe created sinkholes in several part of the territory, causing minibus and car plunging into the holes.

The Hong Kong Government released a brief statement sixteen minutes into Friday, confirming the Shenzhen Reservoir will discharge water from about midnight, and warned that "[t]here may be a risk of flooding in some parts of the New Territories".

[25] However, the Government only "reminded" employers that all non-essential employees "should not be required to report for duty",[26] under a non-binding "extreme conditions" announcement unlike arrangements for typhoons.