Report on Severe Tropical Storm Tapah (2516)
Severe Tropical Storm Tapah (2516)
5 to 9 September 2025
Tapah was the ninth tropical cyclone affecting Hong Kong in 2025. The Observatory issued the No. 8 Gale or Storm Signal during the passage of Tapah.
Tapah formed as a tropical depression over the central part of the South China Sea about 390 km south-southeast of Dongsha on the night of 5 September, and moved west-northwestwards across the central and northern parts of the South China Sea. It turned to track north-northwestwards towards the coast of western Guangdong on the morning of 7 September, and intensified into a severe tropical storm that night. Tapah attained its peak intensity in the small hours of 8 September, with an estimated maximum sustained wind of 110 km/h near its centre. It made landfall near Taishan of Guangdong that morning, then gradually turned northwestwards and moved inland, where it weakened rapidly. Tapah finally degenerated into an area of low pressure in Guangxi on the morning of 9 September.
According to press reports, the southwest monsoon and Tapah brought heavy rain to the Philippines, affecting over 83 000 people. During the passage of Tapah over southern China, accumulated rainfall in parts of Jiangmen and Zhuhai of Guangdong reached 434 millimetres, and hourly rainfall in Haikou of Hainan reached 124 millimetres. In Hainan, Guangdong, Guangxi, and Yunnan, more than 290 000 people were affected and over 210 000 were evacuated during the passage of Tapah. In Macau, there were four injuries and 25 incident reports. At least 81 flights were cancelled at the Macau International Airport.
The Standby Signal No. 1 was issued at 10:20 p.m. on 5 September, when Tapah was about 680 km southeast of Hong Kong. Local winds were light to moderate east to northeasterlies the next day. With Tapah gradually approaching the coast of Guangdong, the No. 3 Strong Wind Signal was issued at 2:40 a.m. on 7 September, when Tapah was about 440 km south of Hong Kong. Winds over Hong Kong strengthened gradually that day and were generally fresh to strong easterlies during the day. As Tapah further intensified and continued to edge closer to the vicinity of the Pearl River Estuary, the gale force winds associated with Tapah were expected to affect Hong Kong and the No. 8 Southeast Gale or Storm Signal was issued at 9:20 p.m. on 7 September when Tapah was about 260 km south-southwest of Hong Kong. Local winds strengthened further the next morning, with generally strong to gale force southeasterlies, and even reached storm force offshore and on high ground.
Tapah came closest to Hong Kong at around 8 a.m. on 8 September, when it skirted past about 170 km west-southwest of the territory. With Tapah moving inland and departing from the territory, local winds weakened gradually in the afternoon. The No. 3 Strong Wind Signal and the No. 1 Standby Signal were issued at 1:10 p.m. and 7:40 p.m. on 8 September. As Tapah weakened further and moved further away from Hong Kong, all tropical cyclone warning signals were cancelled at 4:20 a.m. on 9 September.
Under the influence of Tapah, maximum hourly mean winds of 88, 81 and 78 km/h and gusts of 124, 103 and 151 km/h were recorded at Cheung Chau, Waglan Island, and Ngong Ping respectively. A maximum sea level (above chart datum) of 3.46 m and a maximum storm surge (above astronomical tide) of 0.62 m were recorded at Tsim Bei Tsui. The lowest instantaneous mean sea-level pressures recorded at some selected stations are as follows:
| Station | Lowest instantaneous mean sea-level pressure (hPa) |
Date/Month | Time |
|---|---|---|---|
| Hong Kong Observatory Headquarters | 1001.7 | 8/9 | 5:45 a.m. |
| Hong Kong International Airport | 1000.6 | 8/9 | 6:40 a.m. |
| Cheung Chau | 1000.6 | 8/9 | 6:38 a.m. |
| King’s Park | 1001.8 | 8/9 | 5:45 a.m. |
| Lau Fau Shan | 1001.0 | 8/9 | 5:58 a.m. |
| Peng Chau | 1001.1 | 8/9 | 5:26 a.m. |
| Sha Tin | 1003.3 | 8/9 | 4:55 a.m. |
| Sheung Shui | 1001.3 | 8/9 | 6:01 a.m. |
| Ta Kwu Ling | 1001.8 | 8/9 | 6:05 a.m. |
| Tai Po (Yuen Chau Tsai Park) | 1002.6 | 8/9 | 5:56 a.m. |
| Waglan Island | 1001.1 | 8/9 | 4:35 a.m. |
Under the influence of an anticyclone aloft, the weather of Hong Kong was generally fine and extremely hot on 5 – 6 September. As the rainbands of Tapah approached Hong Kong, the local weather deteriorated gradually the next day, with occasional squally showers and thunderstorms. There were heavy squally showers on 8 September, more than 100 millimetres of rainfall were recorded over many places of the territory. Affected by a southerly airstream, there were still occasional showers and isolated thunderstorms on 9 September.
During the passage of Tapah, at least 12 people were injured in Hong Kong. Locally, there were at least 524 reports of fallen trees and three reports of flooding. A runway excursion incident occurred at Hong Kong International Airport on the morning of 8 September. A passenger aircraft veered to the right while landing on the north runway, damaging three runway edge lights and two Movement Area Guidance Signs on the grass area. The aircraft’s landing gear, right engine and fuselage were damaged. About 140 flights were cancelled and 21 flights were diverted at the Hong Kong International Airport. There were at least six reports of ships damaged in Hong Kong waters.