Report on Typhoon Wipha(2506)
Typhoon Wipha (2506)
16 to 23 July 2025
Wipha was the fourth tropical cyclone affecting Hong Kong in 2025. Since Super Typhoon Saola hitting Hong Kong in 2023, Wipha necessitated the issuance of the Hurricane Signal No. 10 again in just two years.
Wipha formed as a tropical depression over the western North Pacific about 950 km east of Manila on the night of 16 July. It tracked northwestwards towards the Luzon Strait and intensified gradually into a tropical storm in the following two days. Wipha turned to move west-northwestwards across the Luzon Strait on the night of 18 July. It entered the northern part of the South China Sea on 19 July, edging closer to the coast of Guangdong and intensifying rapidly. It intensified into a typhoon that night and attained its peak intensity with an estimated maximum sustained wind of 140 km/h near its centre during its approach to Hong Kong on the morning of 20 July. It moved westwards across the coastal areas of western Guangdong, made landfall near Taishan of Guangdong and weakened gradually later that day. Wipha adopted a west-southwesterly track across Beibu Wan and the northern part of Vietnam and weakened progressively into a tropical depression in the following two days. Wipha finally degenerated into an area of low pressure over Laos on the morning of 23 July.
According to press reports, Wipha, together with the southwest monsoon, brought torrential rain and squalls to the Philippines, causing 6 deaths, 5 injuries and 6 missing. More than 1.26 million people were affected and more than 1 500 houses were damaged, with economic loss exceeding PHP 460 million. Under the influence of the outer rainbands of Wipha, there was torrential rain over the eastern part of Taiwan on 18 – 20 July, with accumulated rainfall reaching 620 millimetres in Taitung. Wipha also caused damage to infrastructure and aquaculture in Guangdong, Guangxi and Hainan, resulting in direct economic losses estimated at about RMB 1.91 billion. In Macau, there were five injuries and 163 incident reports. 160 flights were cancelled at Macau International Airport. Besides, Wipha also brought torrential rain to the northern part of Vietnam, causing flooding and landslides in Thanh Hoa, submerging roads and homes.
The Standby Signal No. 1 was issued at 2:20 a.m. on 19 July, when Wipha was about 780 km east-southeast of Hong Kong. Local winds were moderate to fresh northerlies that morning. With Wipha gradually edging closer to the coast of Guangdong, the No. 3 Strong Wind Signal was issued at 2:20 p.m. that day, when Wipha was about 540 km east-southeast of Hong Kong. Under the influence of the intense rainbands of Wipha, local winds strengthened that night, reaching strong force at many places.
Since Wipha was expected to come rather close to the vicinity of the Pearl River Estuary on 20 July, the No. 8 Northeast Gale or Storm Signal was issued at 12:20 a.m. on 20 July when Wipha was about 270 km east-southeast of Hong Kong. Local winds further strengthened in the small hours, with strong to gale force northerlies affecting many places. With Wipha further approaching Hong Kong with typhoon intensity, its hurricane force winds were expected to be rather close to the territory. The Increasing Gale or Storm Signal No. 9 was issued at 7:20 a.m. that day when Wipha was about 110 km southeast of Hong Kong. Local winds strengthened significantly afterwards, with gale to storm force north to northeasterlies generally over the territory. Since the eyewall of Wipha and its associated hurricane force winds were expected to lash Hong Kong, the Hurricane Signal No. 10 was issued at 9:20 a.m. that day when Wipha was about 70 km southeast of the Observatory Headquarters. Many places of the territory were affected by storm force east to northeasterlies that morning, whereas the southern part of the territory and high ground were persistently battered by hurricane force winds. Wipha came closest to Hong Kong at around 11 a.m. that morning when its centre was located at about 60 km to the south of the Observatory Headquarters.
With Wipha skirting past south of Hong Kong, local winds veered to east to southeasterlies gradually. Wipha departed from Hong Kong gradually in the afternoon. When hurricane force winds no longer posed threat to the territory, the No. 8 Southeast Gale or Storm Signal was issued at 4:10 p.m. on 20 July to replace the Hurricane Signal No. 10. As Wipha weakened and continued to depart from Hong Kong, the No. 3 Strong Wind Signal and the No. 1 Standby Signal were issued at 7:40 p.m. that night and at 3:20 a.m. the next day respectively, and all tropical cyclone warning signals were cancelled at 5:10 a.m. on 21 July.
Satellite imagery (Figure 4b) showed that while Wipha skirted past south of Hong Kong on the morning of 20 July, a “convective hot tower” developed near its centre with violent upward convective motion. Meanwhile, the overlay image of the radar echoes with lightning location information (Figure 5a) showed that there were intense convections near the eyewall south of Wipha, accompanied by lightning during Wipha’s rapid intensification. Besides, radar imagery (Figures 5a and b) showed the eyewall of Wipha impacted Hong Kong that day, bringing hurricane force winds to the southern part of the territory and high ground. Maximum hourly mean winds of 147, 127 and 121 km/h and gusts of 234, 156 and 173 km/h were recorded at Ngong Ping, Waglan Island and Cheung Chau Beach respectively. During the passage of Wipha, the overall wind strength in Hong Kong was similar to those of Hato in 2017 and Saola in 2023, but weaker than that of Mangkhut in 2018 (Table 2).
Under the influence of Wipha, a maximum sea level of 3.03 m (above chart datum) and a maximum storm surge of 1.61 m (above astronomical tide) were recorded at Tai Po Kau. 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 | 980.1 | 20/7 | 10:10 a.m. |
| Hong Kong International Airport | 978.8 | 20/7 | 11:33 a.m. |
| Cheung Chau | 975.8 | 20/7 | 11:07 a.m. |
| King’s Park | 980.4 | 20/7 | 10:12 a.m. |
| Lau Fau Shan | 982.6 | 20/7 | 11:08 a.m. |
| Peng Chau | 977.9 | 20/7 | 11:05 a.m. |
| Sha Tin | 983.2 | 20/7 | 8:52 a.m. |
| Sheung Shui | 983.2 | 20/7 | 10:04 a.m. |
| Ta Kwu Ling | 983.9 | 20/7 | 9:08 a.m. |
| Tai Po (Yuen Chau Tsai Park) | 984.3 | 20/7 | 8:58 a.m. |
| Waglan Island | 974.0 | 20/7 | 10:27 a.m. |
Locally, it was very hot with sunny periods on 19 July under the influence of Wipha’s outer subsiding air. The intense rainbands associated with Wipha started to affect Hong Kong that night. There were squally showers and thunderstorms on 20 July, with more than 70 millimetres of rainfall generally recorded over Hong Kong and rainfall even exceeding 200 millimetres over parts of the territory. Under the influence of the outer rainbands associated with Wipha, there were still occasional showers and squally thunderstorms on 21 July.
In Hong Kong, at least 33 people were injured during the passage of Wipha. There were at least 2 672 reports of fallen trees and seven reports of flooding. Over 500 flights were cancelled at the Hong Kong International Airport. There were at least 600 road incident reports, including blockage of roads due to fallen trees, scaffoldings or flooding. There were five reports on collapsed scaffolds and 21 reports of building-related incidents, which mainly involved unstable windows. Public utilities, including traffic lights and lampposts in many areas were damaged. About 300 hectares of farmland in the New Territories were affected. Mariculture rafts and facilities were also damaged by the winds and waves. A three-story sightseeing ferry drifted off Kennedy Town and collided with a wharf in wind waves.