July 2025: Hong Kong Sees Significant Rainfall After Dry Start, Record Temperatures Amidst Tropical Cyclones Wipha and Danas.

A rainy July with strike of Wipha

After a very dry first half of the year, more significant rainfall eventually returned to Hong Kong in July 2025, mainly due to the passage of the remnant of tropical cyclone Danas in early July and typhoon Wipha in mid-July, as well as showers associated with troughs of low pressure and active southwesterly airstreams during the month. Also, the strike of Wipha necessitated the issuance of the Hurricane Signal No. 10 on July 20. The monthly rainfall was 601.7 millimetres, about 56 per cent above the normal of 385.8 millimetres. However, with the rainfall well below normal in the first half of the year, the accumulated rainfall recorded in the first seven months of the year was only 1 046.1 millimetres, still a deficit of 29 per cent compared to the normal of 1 468.2 millimetres for the same period. The month was also warmer than usual with the monthly mean maximum temperature of 32.4 degrees, 0.8 degrees above the normal and one of the ninth highest on record for July. The monthly mean temperature of 29.5 degrees and monthly mean minimum temperature of 27.4 degrees were 0.6 degrees and 0.5 degrees above their respective normals.

A broad trough of low pressure and upper-air disturbances brought showers and thunderstorms to Hong Kong on the first day of the month. More than 40 millimetres of rainfall were recorded over Lamma Island and the northeastern part of the New Territories. With the establishment of an anticyclone aloft over southern China, apart from isolated showers and thunderstorms, the weather was generally fine and very hot in the following three days.

Moreover, Danas formed as a tropical depression over the northeastern part of the South China Sea on the morning of July 4 and moved northwestwards slowly. It turned to move northeastwards on the next day. Danas intensified progressively into a severe typhoon and made landfall over the western coast of Taiwan on the night of July 6. Danas then entered the East China Sea and weakened progressively into a tropical storm. Locally, apart from isolated showers and squally thunderstorms, it was sunny and extremely hot from July 5 to 7. Temperatures over many places rose to around 35 degrees. On July 7, the maximum temperature recorded at the Observatory was 34.3 degrees, the hottest Moderate Heat ever recorded.

Under the influence of a southwesterly airstream, the weather remained very hot with a mixture of sunshine and showers on July 8 and 9. Meanwhile, Danas made a second sharp turn over the East China Sea on July 8, and made landfall near Wenzhou, Zhejiang, that night. It finally degenerated into an area of low pressure over Fujian on the night of July 9. The remnant of Danas continued to track southwestwards and edge closer to Guangdong. Under the influence of the remnant of Danas and an active southwest monsoon, there were outbreaks of showers and thunderstorms on the night of July 9, and from July 10 to 12. Showers were particularly heavy on the night of July 9 and 10, and more than 100 millimetres of rainfall were generally recorded over the territory. Rainfall even exceeded 200 millimetres over Tsuen Wan and Tsing Yi. The Red Rainstorm Warning was issued three times during the period. Under the heavy rain, temperatures at the Hong Kong Observatory also fell to a minimum of 25.0 degrees on the morning of July 10, the lowest of the month. While there were still showers and thunderstorms from July 13 to 15, it was also very hot with sunny periods under the influence of an anticyclone aloft.

The weather was generally fine and extremely hot during the days on July 16 and 17. Under light wind conditions, heavy showers and thunderstorms triggered by high temperatures affected Hong Kong during the day on July 18. More than 30 millimetres of rainfall were recorded over many places and a severe rainstorm of more than 100 millimetres of hourly rainfall were recorded over Yuen Long District at noon.

Furthermore, Wipha formed as a tropical depression over the seas east of the Philippines on July 16. It then tracked northwestwards towards the Luzon Strait and intensified into a tropical storm on July 18. Wipha moved across the northern part of the South China Sea on July 19 and intensified into a typhoon at night. It skirted about 60 kilometres south of the Hong Kong Observatory towards noon on July 20 and moved across the vicinity of the coast of western Guangdong and towards Beibu Wan afterwards.

Locally, it was very hot with sunny periods on July 19 under the influence of Wipha's outer subsiding air. With Wipha edging closer to the coast of Guangdong gradually, its outer rainbands started to bring squally showers and thunderstorms to the territory at night. As Wipha came quite close to Hong Kong on July 20, many places were affected by storm to hurricane force winds during the day. The maximum 60-minute mean wind speeds recorded at Waglan Island and Cheung Chau were 131km per hour and 115km per hour respectively. With Wipha departing from Hong Kong and weakening gradually, local winds moderated later on July 20. More than 70 millimetres of rainfall were generally recorded over Hong Kong on July 20, and rainfall even exceeded 200 millimetres over parts of the territory. According to preliminary reports, more than 33 people were injured during the passage of Wipha. There were at least 2 284 reports of fallen trees, seven reports of flooding and five reports of collapsed scaffolding. More than 500 flights were cancelled at Hong Kong International Airport. Under the influence of the outer rainbands associated with Wipha, there were still occasional showers and squally thunderstorms on July 21.

A broad trough of low pressure affected the coast of Guangdong and the northern part of the South China Sea on July 22. Locally, the heavy showers on the night of July 22 generally brought more than 40 millimetres of rainfall to the territory. Local weather was generally fine with prolonged heat during the day from July 23 to 27. The maximum temperature at the Observatory rose to 35.2 degrees on the afternoon of July 26, the highest of the month. High temperatures also triggered showers and squally thunderstorms from July 23 to 25. Heavy thundery showers on the evening of July 25 brought more than 50 millimetres of rainfall to parts of the territory, and rainfall even exceeded 90 millimetres over Sai Kung District. Violent gusts of around 110km per hour were recorded at Sai Kung.

While it was very hot with sunny intervals at first on July 28, with an area of thundery showers edging closer to the coastal areas, there were occasional showers and a few thunderstorms later on that day. A broad trough of low pressure brought occasional showers and thunderstorms to Hong Kong on July 29 and 30. The heavy downpour on the morning of July 29 necessitated the issuance of the first Black Rainstorm Warning of the year. More than 70 millimetres of rainfall were recorded over many places, and rainfall even exceeded 200 millimetres over the eastern part of Hong Kong Island, Sai Kung District and Lamma Island. There were eight reports of flooding in Hong Kong. Under the influence of a southwesterly airstream, the weather of Hong Kong was a mixture of sunshine and showers on the last day of the month.

Eight tropical cyclones occurred over the South China Sea and the western North Pacific in July 2025.

Details of issuance and cancellation of various warnings/signals in the month are summarised in Table 1. Monthly meteorological figures and departures from normal for July are tabulated in Table 2.

Source: AI-found images

CHP urges public to promptly receive seasonal influenza vaccination as another severe paediatric influenza infection case reported

The Centre for Health Protection (CHP) of the Department of Health (DH) today (January 18) recorded a severe paediatric influenza infection case. The CHP again reminded parents to arrange for their children to receive a free seasonal influenza vaccination (SIV) promptly. The SIV remains one of the most effective methods of preventing influenza and its complications, and can reduce the risk of serious complications or death from infection.

The case involves a 14-year-old boy with underlying illness. He developed a fever, shortness of breath and productive cough since January 16. He sought medical attention at the Accident and Emergency Department of Pamela Youde Nethersole Eastern Hospital on January 17 and was transferred to the paediatric intensive care unit for further management on the same day. He is currently in critical condition. His respiratory specimen tested positive for influenza A virus upon laboratory testing. The clinical diagnosis is influenza A infection complicated with severe pneumonia and septic shock.

A preliminary investigation revealed that the boy received the 2025/26 SIV only three days before onset of illness. As it generally takes two weeks for the body to develop sufficient protection after vaccination, the boy was not protected by the vaccine. Therefore, it is not counted as being vaccinated. The boy had no travel history during the incubation period. Two of his household contacts developed mild respiratory symptoms earlier. The nasal swab sample of one of the household contacts tested positive for influenza A virus via rapid antigen test. The symptoms were mild and hospitalisation was not required.

The summer influenza season just ended had recorded 25 severe paediatric influenza cases, including three fatal cases. The affected children were aged between 6 months to 17 years old. Among them, 20 cases (80 per cent) had not received an SIV (including one case who received the 2025/26 SIV only four days before onset of illness).

"The summer influenza season was ended. However, influenza activity may rise again as the weather remains cold in the first quarter of this year and it cannot be ruled out that the circulating virus strains may change as the winter influenza season approaches. Therefore, I once again urge all individuals aged 6 months or older, except those with known contraindications, to act promptly if they have not yet received an SIV. This includes those who contracted influenza during the summer influenza season in order to guard against other circulating virus strains that may emerge during the upcoming winter influenza season. Furthermore, although there are some antigenic differences between the currently circulating influenza A (H3) virus strain and the virus strain contained in the vaccine, scientific research indicates that this season's influenza vaccines can still offer protection against the variant strain of subclade K, as well as the influenza A (H1) and influenza B strains included in the vaccine," the Controller of the CHP, Dr Edwin Tsui, said.

"Although the influenza activity has declined to below the baseline level at the moment, outbreaks caused by influenza viruses still occurred in schools and residential care homes. For children who did not join the SIV School Outreach Programme, parents should promptly bring their children toprivate doctorsenrolled in the Vaccination Subsidy Scheme to receive an SIV. In addition, the SIV coverage rate for children aged 6 months to under 2 years is only about 23 per cent. Although this represents an approximate 4 percentage point increase compared to the same period last year, it is still much lower than that of other age groups. Through the Primary Healthcare Commission, the CHP has urged family doctors to assist in encouraging parents to allow their children to receive an SIV," Dr Tsui added.

He also reminded members of the public that, especially for children, the elderly and those with underlying illnesses, they should seek medical advice promptly for early treatment if they present with fever and respiratory symptoms. As children with influenza can deteriorate rapidly, parents must pay close attention to their children's condition. They should go to an Accident and Emergency Department immediately if the child's condition deteriorates, for example, if they develop symptoms such as shortness of breath, wheezing, blue lips, chest pain, confusion, a persistent fever or convulsions.

Separately, high-risk individuals should wear surgical masks when staying in crowded places. People with respiratory symptoms, even if mild, should wear a surgical mask and seek medical advice promptly. They should also consider whether to attend work or school.

In addition to issuing timely reminders to healthcare professionals and schools based on the latest seasonal influenza development, the CHP also uploads the latest seasonal influenza information on its website weekly. Members of the public can visit the CHP'sseasonal influenzaandCOVID-19 & Flu Expresswebpages.

Source: AI-found images