June had outbreaks of heavy rain
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Winds were weak over the coast of Guangdong on the first four days of the month. Locally, there were sunny intervals and afternoon isolated showers on June 1. While there were still some isolated showers, the weather turned mainly fine and very hot on the next three days. Meanwhile, an area of low pressure over the northeastern part of the South China Sea intensified into a tropical depression in the morning of June 4 and moved across the southern part of Taiwan the next day. Under the continued influence of light wind conditions, it was very hot with sunny periods on June 5 and the temperature at the Hong Kong Observatory soared to the month's highest of 34.6 degrees in the afternoon of June 5, the hottest Corn on Ear (a traditional Chinese solar term) on record. Moreover, heat-triggered severe squally thundery showers started to affect Hong Kong that afternoon, bringing more than 10 millimetres of rainfall in Tuen Mun and Tsuen Wan and around 50 millimetres on the western part of Hong Kong Island.
A broad trough of low pressure brought showers and thunderstorms to the coast of Guangdong the next two days. Locally, it was mainly cloudy with showers and squally thunderstorms. More than 60 millimetres of rainfall were recorded over many places, and rainfall even exceeded 100 millimetres over Sai Kung District on these two days. A trough of low pressure formed over the northern part of Guangdong on June 8, and gradually edged closer to the coastal area. Together with the moisture provided by the active southwest monsoon, local weather remained mainly cloudy with showers and squally thunderstorms. Showers were heavy at times and brought more than 70 millimetres of rainfall to most parts of the territory. The maximum hourly rainfall over Sha Tin District even exceeded 100 millimetres that night. Violent gusts of around 100 kilometres per hour were also recorded in Kwai Chung. The incessant downpour necessitated the issuance of the first Black Rainstorm Warning Signal of the year that night. With the southward departure of the trough of low pressure to the northern part of the South China Sea, local weather remained mainly cloudy and showers abated the next day.
Affected by an easterly airstream, local weather was mainly cloudy with one or two showers from June 10 to 12. With the southwest monsoon affecting the coast of Guangdong, the weather in Hong Kong became unsettled with occasional showers and squally thunderstorms the next day. Showers were heavy at times. More than 40 millimetres of rainfall were recorded over many places, and rainfall even reached 100 millimetres over Tsuen Wan District and the eastern part of Lantau Island. Under the influence of a trough of low pressure and a strong southwest monsoon, it was cloudy with heavy showers and squally thunderstorms from June 14 to 16. More than 150 millimetres of rainfall were recorded over most parts of the territory, and rainfall even exceeded 250 millimetres over Hong Kong Island, Sai Kung District and Lantau Island on these three days.
While showers subsided very slightly on June 17 as the trough of low pressure moved north, heavy showers with squally thunderstorms associated with an active southerly airstream and upper-air disturbances affected the territory on June 18. More than 70 millimetres of rainfall were recorded over many places, and rainfall even exceeded 200 millimetres over parts of the New Territories and Lantau Island. Around 3 000 strokes of cloud-to-ground lightning were recorded within Hong Kong. The outbreaks of heavy showers necessitated the issuance of the second and third Black Rainstorm Warning Signals of the year on the same day with an interval of only three hours and 30 minutes. This was the first time two Black Rainstorm Warning Signals were issued in one day and the shortest break between two Black Rainstorm Warning Signals since the commencement of the rainstorm warning system in 1992. In the midst of the incessant downpour, the temperature at the Observatory dropped to the month's lowest of 24.2 degrees that afternoon.
A southerly airstream affected the coast of Guangdong the next two days. Locally, it was mainly cloudy with a few showers. There were sunny intervals during the day. With the establishment of the subtropical ridge and the subsequent anticyclone aloft, the weather in Hong Kong became very hot and mainly fine apart from isolated heat-triggered showers from June 21 to 24. With the anticyclone weakening, apart from sunny intervals on June 25, there were a few showers and thunderstorms with more than 20 millimetres of rainfall recorded over parts of Kowloon and the New Territories. Under the influence of a trough of low pressure, local weather was mainly cloudy with occasional showers and squally thunderstorms on June 26. It was hot with sunny intervals in the morning, but showers were heavy around noon. More than 50 millimetres of rainfall were recorded over many places, and rainfall even reached 70 millimetres over parts of the New Territories and Lantau Island. The trough of low pressure continued to bring showers to the northern part of the South China Sea on June 27, while there were sunny intervals and a few showers in Hong Kong. Showers and thunderstorms associated with the trough of low pressure affected the coast of Guangdong on June 28. More than 40 millimetres of rainfall were recorded over many places. Following the gradual weakening of the trough of low pressure, a southerly airstream affected the coast of Guangdong in the last two days of the month. Locally, the weather was mainly cloudy with a few showers and thunderstorms. There were sunny periods during the day. More than 20 millimetres of rainfall were recorded over many places, and rainfall even exceeded 40 millimetres over Kowloon East, the New Territories East and Lantau Island on these two days.
Four tropical cyclones occurred over the South China Sea and the western North Pacific in June 2026.
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 June are tabulated in Table 2.
Ends/Friday, July 3, 2026
Issued at HKT 16:00
Issued at HKT 16:00
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