Fact · extreme-weather · 2023-09-07
Record highest one-hour rainfall
歷史最高一小時雨量紀錄
Figure and reference date
158.1 mm (7 Sep 2023, HKO)
158.1 毫米（2023年9月7日，天文台總部）
Notes and definition
HKO report on Severe Typhoon Haikui (2311), breaking records since 1884.
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 |
|---|---|---|---|
| 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 |
| Flooding reports / blackspots 水浸報告／黑點 | 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 DSD nomenclature; blackspot list carries grading codes. | 2026 | Drainage Services Department: flooding reports and blackspots |
Other figures from the same official source
These figures come from the same registered document: “Hong Kong Observatory: report on Severe Typhoon Haikui (2311)” (Hong Kong Observatory). Being in one document does not make them additive.
| Item / 項目 | Figure / 數字 | As of / 時點 | Source / 來源 |
|---|---|---|---|
| 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) |
How to cite this figure
Hong Kong Story, “Record highest one-hour rainfall”, https://hongkongstory.org/en/facts/xwx-max-1hr-rain-2023, data as at 2023-09-07 (retrieved ＿).
中文：香港紀事館，〈歷史最高一小時雨量紀錄〉，https://hongkongstory.org/facts/xwx-max-1hr-rain-2023，資料時點 2023-09-07（查閱日期 ＿）。
Machine-readable: /api/v1/facts.json (id = xwx-max-1hr-rain-2023) · OpenAPI 3.1 ·/llms.txt
Registered source
Hong Kong Observatory: report on Severe Typhoon Haikui (2311)
Hong Kong Observatory
The official document carries no registered publication date, so only the retrieval date 2026-10-10 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.