2023 Hong Kong rainstorm and floods
In early September 2023, a heavy rainstorm hit Hong Kong and the Pearl River Delta, caused by a low-pressure system from the remnants of Typhoon Haikui that stalled over the area and interacted with the southwest monsoon. The storm lasted from 7 to 8 September 2023 and affected Hong Kong, Macau, and the southern coast of China.
By the evening of 7 September, heavy rain spread across the territory. Sha Tau Kok in the North District recorded more than 70 millimetres of rain in a short time. The Hong Kong Observatory issued flood warnings, first for the Northern New Territories, then Amber, then Red, and finally the Black rainstorm signal by 11:05 pm—the first time the Black signal had been used in two years. From 11 pm on 7 September to 12 am on 8 September, Hong Kong Observatory recorded 158.1 millimetres of rain in one hour, the highest hourly rainfall since records began in 1884. The rainfall continued overnight and into the morning, gradually easing on 8 September. The Black rainstorm signal lasted more than 16 hours, the longest in the system’s history. The total 24-hour rainfall reached about 632 millimetres, making Haikui the wettest storm in Hong Kong’s history, ahead of the 1999 Severe Tropical Storm Sam. Some parts of Hong Kong Island saw exceptional totals, with areas like Tai Tam receiving more than 900 millimetres in 12 hours. Parts of the territory experienced severe flooding and landslides.
The floods caused widespread damage: shopping centres and MTR tunnels were flooded, roads and vehicles were submerged, and landslides blocked roads. Some communities were cut off, and homes near the Sham Chun River were affected after a discharge from the Shenzhen Reservoir began around midnight, raising fears of more floods. All schools in Hong Kong were closed on 8 September, and employers were advised not to require non-essential staff to report to work, though this guidance was non-binding. The government faced criticism over the handling and timing of the warnings, with officials sometimes describing the event as “once-in-a-century” or even “once-in-500-years,” which sparked public debate and calls for a full review of emergency response plans.
Overall, 15 people died (4 in Hong Kong, 11 in Guangxi) and 144 were injured in Hong Kong. The losses were estimated at around HK$100 million. The storm also affected Macau and the southern coast of China.
This page was last edited on 3 February 2026, at 08:59 (CET).