Fact · extreme-weather · 2026
Flooding reports / blackspots
水浸報告／黑點
Figure and reference date
257 flooding reports 2021–23; ~240 susceptible spots statewide
2021-23 共 257 宗水浸報告；官方口徑全港約 240 個易淤塞點
Notes and definition
DSD nomenclature; blackspot list carries grading codes.
Other figures in this group (extreme-weather)
Figures in the same group are not necessarily additive — check the basis note above first. Extreme weather & meteorological records.
| Item / 項目 | Figure / 數字 | As of / 時點 | Source / 來源 |
|---|---|---|---|
| Record highest one-hour rainfall 歷史最高一小時雨量紀錄 | 158.1 mm (7 Sep 2023, HKO) 158.1 毫米（2023年9月7日，天文台總部） HKO report on Severe Typhoon Haikui (2311), breaking records since 1884. | 2023-09-07 | Hong Kong Observatory: report on Severe Typhoon Haikui (2311) |
| Annual landslide reports 全年山泥傾瀉報告宗數 | 601 (2023) 601 宗（2023年） GEO: 76 in 2022; 238 on 8 Sep 2023 in a single rainstorm. | 2023 | CEDD Geotechnical Engineering Office: landslide records |
| Tropical Cyclone Signal No.10 count 十號颶風信號次數 | 16 since 1946 (latest two in 2025) 戰後至今 16 次（最近2025年兩次） HKO historical wind-signal table; highest hourly mean was Wanda, 133 km/h. | 2025 | Hong Kong Observatory: report on Severe Typhoon Haikui (2311) |
| Record one-hour rainfall 歷史最高一小時雨量 | 158.1 mm (2023-09-07); previous 111 mm (1966) 158.1mm（2023-09-07）；舊紀錄111mm（1966） HKO HQ; broke the record going back to 1884. | 2023-09-07 | Hong Kong Observatory: report on Severe Typhoon Haikui (2311) |
| Annual landslide reports 全年山泥傾瀉報告 | 257 in 2025; 601 in 2023 2025 年 257 宗；2023 年 601 宗 212 of the 2025 reports occurred during rainstorm warnings. | 2025 | CEDD Geotechnical Engineering Office: landslide records |
How to cite this figure
Hong Kong Story, “Flooding reports / blackspots”, https://hongkongstory.org/en/facts/xwx-flooding-reports-2021-2023, data as at 2026 (retrieved ＿).
中文：香港紀事館，〈水浸報告／黑點〉，https://hongkongstory.org/facts/xwx-flooding-reports-2021-2023，資料時點 2026（查閱日期 ＿）。
Machine-readable: /api/v1/facts.json (id = xwx-flooding-reports-2021-2023) · OpenAPI 3.1 ·/llms.txt
Registered source
Drainage Services Department: flooding reports and blackspots
Drainage Services Department
The official document carries no registered publication date, so only the retrieval date 2026-10-11 is given — no publication year is invented.
This site is a secondary compilation: the official text prevails. If the figure above differs from the official document, the official document is correct.