Overview of Tropical Cyclone in August 2025

Eleven tropical cyclones occurred over the western North Pacific and the South China Sea in August 2025. Among them, Podul (2511), Kajiki (2513), Nongfa (2514) and a tropical depression necessitated the issuance of the tropical cyclone warning signal by the Observatory.

Co-May (2508) formed as a tropical depression over the Luzon Strait about 470 km north of Manila on the morning of 23 July. Under the Influence of Francisco (2507) over the vicinity of the Ryukyu Islands, Co-May made an anti-clockwise loop over the seas west of Luzon and the coastal areas of western Luzon in the following two days. It intensified into a severe tropical storm on the morning of 24 July and attained its peak intensity that night, with an estimated maximum sustained wind of 110 km/h near its centre. It turned to move generally north-northeastwards across the Luzon Strait and the seas east of Taiwan on 25 July, and weakened into a tropical depression the next day. Co-May lingered over the vicinity of the Ryukyu Islands on 27 July. It intensified into a tropical storm again, and gradually turned to move northwestwards towards the vicinity of the Yangtze River Estuary in the following two days. Co-May made successive landfalls over Zhejiang and Shanghai on 30 July. It moved inland and gradually weakened the next day. Co-May finally degenerated into an area of low pressure in Anhui on 1 August.

According to press reports, Co-May, Francisco and the southwest monsoon brought torrential rain and squalls to the Philippines, with an accumulated rainfall of 1 241.0 millimetres over parts of Luzon on 22 - 30 July. The rain and squalls caused 28 deaths, one missing and 24 injuries in the Philippines. Over 9.8 million people were affected, and more than 100 000 houses were damaged, with economic loss exceeding PHP 20.9 billion. Co-May also brought torrential rain and squalls to Zhejiang, Shanghai, Jiangsu and Anhui, with over 450 000 people affected and an estimated economic loss of approximately RMB 300 million. In Shanghai, over 280 000 people were evacuated. Approximately 640 flights in total were cancelled at Shanghai Pudong and Hongqiao International Airports.

Krosa (2509) formed as a tropical depression over the western North Pacific about 180 km west-northwest of Guam on the morning of 24 July. It moved northwards or north-northeastwards, and intensified gradually in the following three days. Krosa intensified into a typhoon on the morning of 27 July, and attained its peak intensity over the seas east of Iwo Jima in the small hours of the next day, with an estimated maximum sustained wind of 140 km/h. It weakened into a severe tropical storm on 29 July, and moved across the seas southeast of Honshu, Japan in the following three days. Krosa picked up speed and turned to move east-northeastwards on 2 August. It finally evolved into an extratropical cyclone over the western North Pacific to the east of Hokkaido on the afternoon of 4 August.

Originating from the central North Pacific, Iona moved across the International Date Line with tropical depression intensity and entered the western North Pacific around on the afternoon of 2 August. At the time, the maximum sustained wind near its centre was estimated to be 55 km/h, and it tracked generally northwestwards. Iona finally degenerated into an area of low pressure over sea on the afternoon of 4 August.

A tropical depression formed over the western North Pacific about 700 km north of Wake Island on the afternoon of 2 August, and moved generally west-northwestwards. It attained its peak intensity with an estimated maximum sustained wind of 55 km/h near its centre that night. The tropical depression finally degenerated into an area of low pressure over sea on the night of 4 August.

Bailu (2510) formed as a tropical depression over the seas southeast of Honshu, Japan about 320 km south-southeast of Tokyo on the morning of 3 August, and moved generally east-northeastwards. Bailu intensified into a tropical storm on the night of 4 August, attaining its peak intensity with an estimated maximum sustained wind of 65 km/h near its centre. Bailu finally evolved into an extratropical cyclone in the western North Pacific to the east of Japan on the morning of 6 August.

A tropical depression formed over the western North Pacific about 710 km northwest of Wake Island on the afternoon of 4 August, and moved northwestwards. It attained its peak intensity with an estimated maximum sustained wind of 55 km/h near its centre on the night of 5 August, and turned to move generally northwards. The tropical depression finally degenerated into an area of low pressure over the western North Pacific to the east of Japan on the afternoon of 7 August.

Podul (2511) formed as a tropical depression over the western North Pacific about 620 km north-northeast of Guam in the small hours of 7 August, and tracked northwestwards to west-northwestwards, while gradually intensifying. Podul turned to move generally westwards towards the seas east of the Luzon Strait on 9 - 12 August. It rapidly intensified into a severe typhoon, attaining its peak intensity with an estimated maximum sustained wind of 155 km/h in the small hours of 13 August, before making landfall over Taiwan. Podul turned to move west-northwestwards rapidly across the southern part of Taiwan and the Taiwan Strait that day. It made landfall again in Zhangpu of Fujian in the small hours of 14 August, and rapidly weakened into a tropical storm. Podul finally moved into inland areas, and degenerated into an area of low pressure over Guangxi in the small hours of the next day.

According to press reports, during the passage of Podul over Taiwan, a 24-hour rainfall of 644.5 millimetres was recorded in Dahan Shan of Pingtung. Podul caused one death, one missing and 149 injuries in Taiwan. Water and electricity supplies to more than 6 600 and 310 000 households were disrupted respectively. Economic loss exceeded USD 17 million. Air traffic in Taiwan was also affected, with more than 380 flights cancelled. Podul also caused two deaths and affected more than 290 000 people in Fujian, Guangdong, Hunan and other provinces in China. Under the influence of the outer rainbands of Podul, an hourly rainfall of 110.0 millimetres was recorded at Ka Ho of Macau on 14 August, and flooding occurred in many areas of Taipa and Coloane. For detailed information of Podul including its impact to Hong Kong, please refer to the Tropical Cyclone Report of Podul.

A tropical depression formed over the central part of the South China Sea about 130 km southeast of Xisha on the night of 16 August, with an estimated maximum sustained wind of 45 km/h near its centre. It tracked northwestwards or west-northwestwards towards the seas south of Hainan Island. Skirting past the southwestern coast of Hainan Island on 18 August, the tropical depression entered Beibu Wan and gradually turned to move northwards. It made landfall over the northern part of Vietnam in the small hours of 19 August, and finally degenerated into an area of low pressure area in Guangxi that night.

According to press reports, under the combined effect of the tropical depression and a ridge of high pressure over southeastern China, there were torrential rain and squalls over Guangdong, Guangxi, Hainan Island and the northern part of Vietnam. For detailed information of the tropical depression including its impact to Hong Kong, please refer to the Tropical Cyclone Report of the tropical depression.

Lingling (2512) formed as a tropical depression over the western North Pacific about 490 km south of Okinawa on the morning of 18 August, and moved generally northwards across the vicinity of the Ryukyu Islands and the East China Sea in the following two days. Lingling turned to move eastwards on 21 August. It intensified into a tropical storm that morning, attaining its peak intensity with an estimated maximum sustained wind of 65 km/h near its centre. Lingling then moved across the southern part of Kyushu, Japan, and weakened gradually. It finally degenerated into an area of low pressure area over the coastal waters south of Shikoku, Japan on the afternoon of 22 August.

According to press reports, Lingling brought torrential rain and squalls to the southern part of Kyushu, Japan, with a 24-hour rainfall of more than 300 millimetres recorded over Kagoshima Prefecture. Lingling caused five injuries, and at least four houses were damaged in Japan. Water and electricity supplies to approximately 80 and 340 households were disrupted respectively.

Kajiki (2513) formed as a tropical depression over the seas east of Luzon about 320 km east-northeast of Manila in the small hours of 22 August, then moved westwards to west-northwestwards across Luzon, and entered the central part of the South China Sea. During its passage across the central part of the South China Sea on 23 - 24 August, Kajiki rapidly intensified from a tropical depression into a severe typhoon and attained its peak intensity over the seas south of Hainan Island on the evening of 24 August, with an estimated maximum sustained wind of 165 km/h near its centre. Kajiki made landfall over the northern part of Vietnam on the evening of the next day, and weakened rapidly. Kajiki finally degenerated into an area of low pressure over Lao PDR in the small hours of 27 August.

According to press reports, under the combined effect of Kajiki and the southwest monsoon, there were torrential rain and squalls over the central and northern parts of the Philippines. There were over 110 000 people affected and more than 60 houses damaged. Kajiki also brought torrential rain and squalls to Hainan, Guangxi and Guangdong, with a 24-hour rainfall of 508.8 millimetres recorded over Sansha of Hainan. There was one dead or missing, and over 200 000 people affected in Hainan and Guangxi. During passage of Kajiki over the central and northern parts of Vietnam, it triggered river flooding and landslides over many places, causing at least six deaths, two missing, 47 injuries and over 1.5 million people affected. More than 30 000 houses and over 120 000 hectares of crops were damaged. The torrential rain associated with Kajiki and its remnant also caused flooding and landslides in Lao PDR, Thailand, and Myanmar. There were eight deaths, three missing and at least four injuries in Thailand, whereas there were at least two deaths and 15 injuries in Myanmar. For detailed information of Kajiki including its impact to Hong Kong, please refer to the Tropical Cyclone Report of Kajiki.

Nongfa (2514) formed as a tropical depression over the central part of the South China Sea about 410 km east-southeast of Xisha on the afternoon of 28 August, and moved generally west-northwestwards. It turned to track westwards across the seas south of Hainan Island on the night of the next day. Nongfa intensified into a tropical storm over the seas southwest of Hainan Island on the morning of 30 August, attaining its peak intensity with an estimated maximum sustained wind of 65 km/h near its centre. It made landfall over the central part of Vietnam that afternoon and weakened gradually. Nongfa finally degenerated into an area of low pressure in the northern part of Thailand on the morning of 31 August.

According to press reports, Nongfa and the southwest monsoon brought heavy rain to the Philippines. More than 250 000 people were affected and over 470 houses were damaged. The heavy rain associated with Nongfa also caused at least one death in Vietnam, and two deaths and more than 490 houses damaged in Thailand. For detailed information of Nongfa including its impact to Hong Kong, please refer to the Tropical Cyclone Report of Nongfa.