Report on Severe Typhoon Danas (2504)

Severe Typhoon Danas (2504)
4 to 9 July 2025

Danas was the third tropical cyclone affecting Hong Kong in 2025.

Danas formed as a tropical depression over the northeastern part of the South China Sea about 280 km east-southeast of Dongsha on the morning of 4 July and moved west-northwestwards slowly. It intensified into a tropical storm in the small hours of the next day. Danas made the first sharp turn on 5 July, taking a north-northeasterly or northeasterly track. It started to pick up speed on 6 July and rapidly intensified into a severe typhoon just before making landfall over Chiayi of Taiwan that night, attaining its peak intensity with an estimated maximum sustained wind of 155 km/h near its centre. Danas weakened when it moved across Taiwan. It then entered the East China Sea and continued to move northeastwards during the day on 7 July. Danas made the second sharp turn over the East China Sea on 8 July, moving west-southwestwards towards Zhejiang. It made landfall again over Wenzhou of Zhejiang that night. It then moved inland via a southwesterly track and weakened. Danas finally degenerated into an area of low pressure over Fujian on the night of 9 July.

According to press reports, Danas, together with the southwest monsoon, brought heavy rain to the northern part of the Philippines, causing one death and affecting approximately 100 000 people. Economic loss exceeded PHP 12.4 million. Danas brought torrential rain and squalls to Taiwan during its passage from the night of 6 July to the next morning. Danas and the active southwest monsoon continued to bring torrential rain to Taiwan in the following three days. A maximum accumulated rainfall of over 1 100 millimetres was recorded in Pingtung during this period. Torrential rain and squalls resulted in two deaths and at least 700 injuries. Water and electricity supplies to more than 70 000 and one million households were disrupted respectively. Over 18 000 houses were damaged. Economic loss exceeded USD 51 million. Affected by Danas, its remnant and the active southwest monsoon, there was persistent heavy rain over Zhejiang, Fujian and Guangdong on 8 – 12 July.

The Standby Signal No. 1 was issued at 12:20 p.m. on 4 July, when Danas was about 530 km east-southeast of Hong Kong. Local winds were moderate to fresh east to northeasterlies the next day, occasionally strong offshore and on high ground later. Danas came closest to Hong Kong at around 5 a.m. on 5 July, skirting past about 410 km southeast of the territory. With Danas picking up speed moving towards the vicinity of the western coast of Taiwan, it no longer posed a threat to Hong Kong and all tropical cyclone warning signals were cancelled at 2:20 p.m. on 6 July.

Danas did not cause any significant damage when it affected Hong Kong. At the Observatory Headquarters, the lowest instantaneous mean sea-level pressure of 1001.1 hPa was recorded at 2:16 p.m. on 6 July. Under the influence of Danas, a maximum sea level of 2.47 m (above chart datum) was recorded at Tsim Bei Tsui and a maximum storm surge of 0.49 m (above astronomical tide) was recorded at Tai Po Kau.

Apart from isolated showers and squally thunderstorms, the weather in Hong Kong was sunny with prolonged heat on 4 – 7 July. Temperatures over many places rose to about 35 degrees on 5 July. The maximum temperature recorded at the Observatory was 34.3 degrees on 7 July, the hottest Moderate Heat ever recorded. Under the influence of a southwesterly airstream, the weather remained very hot on 8 – 9 July. The remnant of Danas continued to move southwestwards and affected Guangdong from the night of 9 July to 11 July. Under the influence of Danas’ remnant and the active southwest monsoon, there were outbreaks of showers and thunderstorms over Hong Kong between the night of 9 July and 12 July. The showers were particularly heavy from the night of 9 July to the next day. More than 100 millimetres of rainfall were generally recorded over the territory and rainfall even exceeded 200 millimetres over Tsuen Wan and Tsing Yi. Red Rainstorm Warning was issued three times during the period.