The Year’s Weather 2025 – A Stormy 2025
Thursday, 8th January 2026
Fig. 1 Monthly mean temperature anomalies (against the 1991-2020 normal) in Hong Kong in 2025
Fig. 2 Long-term time series of number of hot nights in Hong Kong (1884-2025)
Fig. 3 Long-term time series of number of very hot days in Hong Kong (1884-2025)
Fig. 4 Long-term time series of number of extremely hot days in Hong Kong (1884-2025)
Fig. 5 Long-term time series of number of cold days in Hong Kong (1884-2025)
Fig. 6 Long-term time series of annual mean temperature in Hong Kong (1885-2025)
Fig. 7 Monthly rainfall anomalies (against the 1991-2020 normal) in Hong Kong in 2025
Fig. 8 Annual rainfall distribution in Hong Kong in 2025 (in millimetres)
Detailed description of the weather for individual months is available on the Monthly Weather Summary webpage:
https://www.weather.gov.hk/en/wxinfo/pastwx/mws/mws.htm
Some significant weather events in Hong Kong in 2025 are highlighted below:
The first signal No. 10 in the year - the strike of Typhoon Wipha on 19 – 21 July
Globally, 2025 is on track to be the second or third warmest years on record according to the World Meteorological Organization’s preliminary assessment. Over the Arctic and the Antarctica, sea-ice extent remained well below average during the year. In particular, the Arctic annual maximum sea-ice extent was the lowest in the satellite record. Extreme weather events affected many parts of the world in 2025, including heatwaves in East Asia, Europe and the eastern Mediterranean; severe droughts in southwest Asia and the Amazon basin; severe flooding triggered by extreme rainfall in South Asia, western Nigeria, the Democratic Republic of the Congo, the Eastern Cape of South Africa and Texas of the United States; severe damages and heavy casualties inflicted by tropical cyclones in the Philippines, China, Vietnam, Thailand, Myanmar, Mozambique, Madagascar, the Caribbean, Malaysia and Indonesia. Rampant wildfires exacerbated by high temperatures, dry and windy conditions also wreaked havoc in Europe, the Republic of Korea and California of the United States.
Sea surface temperatures in the central and eastern equatorial Pacific were near normal from January through October 2025, then lingered between below normal and near normal in November and December 2025.
In Hong Kong, with all 12 months warmer than usual, including the record-breaking monthly mean temperature in October, 2025 was the sixth warmest year on record with the annual mean temperature reaching 24.3 degrees, 0.8 degrees above the 1991-2020 normal[1]. The annual mean maximum temperature of 27.1 degrees and annual mean minimum temperature of 22.4 degrees were respectively one of the fifth and one of the sixth highest since records began in 1884. There were 53 very hot days[2] and 54 hot nights[3] in Hong Kong in 2025, both ranking the third highest on record. There were also four extremely hot days[4], ranking one of the fifth highest on record.
The lowest temperature recorded at the Observatory in the year was 10.6 degrees on 27 January. The number of cold days[5] in the year was 6 days, 9.2 days less than the 1991-2020 normal. Moreover, this was also the first time that no Cold Weather Warning was in force in November and December in a year since the Cold Weather Warning System commenced operation in 1999.
Sea surface temperatures in the central and eastern equatorial Pacific were near normal from January through October 2025, then lingered between below normal and near normal in November and December 2025.
In Hong Kong, with all 12 months warmer than usual, including the record-breaking monthly mean temperature in October, 2025 was the sixth warmest year on record with the annual mean temperature reaching 24.3 degrees, 0.8 degrees above the 1991-2020 normal[1]. The annual mean maximum temperature of 27.1 degrees and annual mean minimum temperature of 22.4 degrees were respectively one of the fifth and one of the sixth highest since records began in 1884. There were 53 very hot days[2] and 54 hot nights[3] in Hong Kong in 2025, both ranking the third highest on record. There were also four extremely hot days[4], ranking one of the fifth highest on record.
The lowest temperature recorded at the Observatory in the year was 10.6 degrees on 27 January. The number of cold days[5] in the year was 6 days, 9.2 days less than the 1991-2020 normal. Moreover, this was also the first time that no Cold Weather Warning was in force in November and December in a year since the Cold Weather Warning System commenced operation in 1999.
Fig. 1 Monthly mean temperature anomalies (against the 1991-2020 normal) in Hong Kong in 2025
Fig. 2 Long-term time series of number of hot nights in Hong Kong (1884-2025)
Fig. 3 Long-term time series of number of very hot days in Hong Kong (1884-2025)
Fig. 4 Long-term time series of number of extremely hot days in Hong Kong (1884-2025)
Fig. 5 Long-term time series of number of cold days in Hong Kong (1884-2025)
Fig. 6 Long-term time series of annual mean temperature in Hong Kong (1885-2025)
While the accumulated rainfall recorded in the first half of the year was only 444.4 millimetres, the fifth lowest on record for the same period, with outbreaks of heavy rain during July to September, the annual total rainfall in 2025 was 2,558.7 millimetres, about 5 percent above the 1991-2020 normal of 2,431.2 millimetres. The rainfall was concentrated during July to September and the total rainfall during these three months contributed more than 80 percent of the annual rainfall. There were 16 Red Rainstorm Warnings and five Black Rainstorm Warnings, breaking the respective highest annual numbers on record. The number of days with thunderstorms reported in Hong Kong was 37 days in 2025, 5.3 days less than the 1991-2020 normal.
Fig. 7 Monthly rainfall anomalies (against the 1991-2020 normal) in Hong Kong in 2025
Fig. 8 Annual rainfall distribution in Hong Kong in 2025 (in millimetres)
With the relative humidity well below normal in the first half of the year and in November, the annual mean relative humidity of 73 percent in 2025 was 5 percent below the normal of 78 percent and on par with 1963 as one of the lowest on record since 1947. The low humidity in 2025 is mainly attributed to the drier-than-usual northeast monsoon over southern China from January to April and in November. The stronger-than-normal and more westward extending subtropical ridge in May and June which suppressed the precipitation in Hong Kong also contributed to the relatively drier weather in these two months.
Fig. 9 Monthly mean relative humidity anomalies (against the 1991-2020 normal) in Hong Kong in 2025
A total of 35 tropical cyclones occurred over the western North Pacific and the South China Sea in 2025, more than the long-term (1961-2020) average of about 30. There were 14 tropical cyclones reaching typhoon intensity[6] or above during the year, similar to the long-term average of about 15, and five of them reached super typhoon intensity (with maximum 10-minute wind speed of 185 km/h or above near the centre). In Hong Kong, 14 tropical cyclones necessitated the issuance of tropical cyclone warning signals, more than double of the long-term average of about six in a year, the highest annual number since 1946. The Hurricane Signal No. 10 was issued twice in the year during the passages of Typhoon Wipha in July and Super Typhoon Ragasa in September, tying the previous record in 1964. The No. 8 Gale or Storm Signal was issued during the passage of Severe Tropical Storm Tapah in September.
The record-breaking number of tropical cyclones affecting Hong Kong in the year is mainly attributed to higher-than-normal sea surface temperature over the western North Pacific and the more westward extending subtropical ridge during the summer and autumn, which favoured the tropical cyclones over the western North Pacific and the South China Sea moving towards the northern part of the South China Sea, increasing the chance for them to affect the coast of southern China including Hong Kong.
Fig. 9 Monthly mean relative humidity anomalies (against the 1991-2020 normal) in Hong Kong in 2025
The record-breaking number of tropical cyclones affecting Hong Kong in the year is mainly attributed to higher-than-normal sea surface temperature over the western North Pacific and the more westward extending subtropical ridge during the summer and autumn, which favoured the tropical cyclones over the western North Pacific and the South China Sea moving towards the northern part of the South China Sea, increasing the chance for them to affect the coast of southern China including Hong Kong.
Detailed description of the weather for individual months is available on the Monthly Weather Summary webpage:
https://www.weather.gov.hk/en/wxinfo/pastwx/mws/mws.htm
Some significant weather events in Hong Kong in 2025 are highlighted below:
A dry April with earliest occurrence of very hot weather
With drier northeast monsoon affecting Hong Kong for most of the time and less moisture supply to the coast of southern China in the month, April 2025 was much drier than usual in Hong Kong. The monthly mean relative humidity was 74 percent, the second lowest on record for April. In particular, the relative humidity recorded at the Observatory on 13 April once fell to 21 percent, the lowest record in April since the establishment of the automatic weather station at the Observatory's Headquarters in 1984. With plenty of sunshine and weaker winds on 15 April, the temperature at the Observatory soared to a maximum of 33.0 degrees that afternoon, marking the earliest occurrence of very hot weather in a year and breaking the previous record of 27 April set in 1956.
With drier northeast monsoon affecting Hong Kong for most of the time and less moisture supply to the coast of southern China in the month, April 2025 was much drier than usual in Hong Kong. The monthly mean relative humidity was 74 percent, the second lowest on record for April. In particular, the relative humidity recorded at the Observatory on 13 April once fell to 21 percent, the lowest record in April since the establishment of the automatic weather station at the Observatory's Headquarters in 1984. With plenty of sunshine and weaker winds on 15 April, the temperature at the Observatory soared to a maximum of 33.0 degrees that afternoon, marking the earliest occurrence of very hot weather in a year and breaking the previous record of 27 April set in 1956.
The first signal No. 10 in the year - the strike of Typhoon Wipha on 19 – 21 July
Wipha formed as a tropical depression over the seas east of the Philippines on 16 July and then tracked northwestwards towards Luzon Strait. Wipha moved across the northern part of the South China Sea on 19 July and intensified into a typhoon that night. It skirted about 60 kilometres south of the Hong Kong Observatory at around 11 a.m. on 20 July and moved across the vicinity of the coast of western Guangdong and towards Beibu Wan afterwards.
As Wipha came quite close to Hong Kong on 20 July, the Hurricane Signal No. 10 was issued in the morning and 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 131 km/h and 115 km/h respectively. More than 70 millimetres of rainfall were generally recorded over Hong Kong on that day, and rainfall even exceeded 200 millimetres over parts of the territory. In Hong Kong, at least 33 people were injured during the passage of Wipha. There were at least 2,672 reports of fallen trees, seven reports of flooding, five reports of collapsed scaffolding and 21 reports of building-related incidents. A three-story sightseeing ferry drifted off Kennedy Town and collided with a wharf in wind waves. More than 500 flights were cancelled at the Hong Kong International Airport.
As Wipha came quite close to Hong Kong on 20 July, the Hurricane Signal No. 10 was issued in the morning and 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 131 km/h and 115 km/h respectively. More than 70 millimetres of rainfall were generally recorded over Hong Kong on that day, and rainfall even exceeded 200 millimetres over parts of the territory. In Hong Kong, at least 33 people were injured during the passage of Wipha. There were at least 2,672 reports of fallen trees, seven reports of flooding, five reports of collapsed scaffolding and 21 reports of building-related incidents. A three-story sightseeing ferry drifted off Kennedy Town and collided with a wharf in wind waves. More than 500 flights were cancelled at the Hong Kong International Airport.
Fig. 10 During the passage of Wipha, a three-story sightseeing ferry drifted off Kennedy Town and collided with the wharf in wind waves. (Courtesy of Now News)
The fifth black rainstorm on 14 August
Under the influence of the outer band of intense thundery showers associated with tropical cyclone Podul, there were heavy showers and severe squally thunderstorms in Hong Kong on 14 August. More than 100 millimetres of rainfall were recorded over many places, and rainfall even exceeded 200 millimetres over Lantau Island, Tuen Mun and parts of Hong Kong Island. The incessant downpour necessitated the issuance of the Black Rainstorm Warning for the fifth time in the year, breaking the previous annual record of three times set in 2000 and 2006 since the rainstorm warning system began operation in 1992.
The strike of tropical cyclone Tapah on 7 – 8 September
Five Black Rainstorm Warnings in July and August
There were outbreaks of heavy rain in July and August. A record-breaking number of five Black Rainstorm Warnings were issued by the Observatory in just 17 days, from 29 July to 14 August.
Black rainstorm on 29 July
A broad trough of low pressure brought occasional showers and thunderstorms to Hong Kong on 29 – 30 July. The heavy downpour on the morning of 29 July necessitated the issuance of the first Black Rainstorm Warning in 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.
Three black rainstorms on 2 – 5 August
An active southwest monsoon and upper-air disturbances brought heavy showers and squally thunderstorms to the coast of Guangdong on 2 – 5 August. The outbreaks of heavy showers necessitated the issuance of the Black Rainstorm Warning for three times in just four days. The Observatory headquarters registered a record-breaking daily rainfall of 368.9 millimetres on 5 August, the highest daily rainfall in August since records began in 1884. This daily rainfall amount was already more than 80 percent of the normal rainfall in August. The accumulated rainfall recorded at the Observatory during these four days was near 600 millimetres and rainfall even exceeded 800 millimetres over Tseung Kwan O and Tsz Wan Shan.
Black rainstorm on 29 July
A broad trough of low pressure brought occasional showers and thunderstorms to Hong Kong on 29 – 30 July. The heavy downpour on the morning of 29 July necessitated the issuance of the first Black Rainstorm Warning in 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.
Fig. 11 Flooding in Chai Wan during the rainstorm of 29 July 2025 (Courtesy of HK01 / Photos by Liu Ngan Hung)
Three black rainstorms on 2 – 5 August
An active southwest monsoon and upper-air disturbances brought heavy showers and squally thunderstorms to the coast of Guangdong on 2 – 5 August. The outbreaks of heavy showers necessitated the issuance of the Black Rainstorm Warning for three times in just four days. The Observatory headquarters registered a record-breaking daily rainfall of 368.9 millimetres on 5 August, the highest daily rainfall in August since records began in 1884. This daily rainfall amount was already more than 80 percent of the normal rainfall in August. The accumulated rainfall recorded at the Observatory during these four days was near 600 millimetres and rainfall even exceeded 800 millimetres over Tseung Kwan O and Tsz Wan Shan.
Fig. 12 Rainfall distribution map on 5 August 2025
Fig. 13 A carpark in Tseung Kwan O was flooded on the night of 4 August 2025 (Courtesy of HK01 / Photo by 李家傑)
Under the influence of the outer band of intense thundery showers associated with tropical cyclone Podul, there were heavy showers and severe squally thunderstorms in Hong Kong on 14 August. More than 100 millimetres of rainfall were recorded over many places, and rainfall even exceeded 200 millimetres over Lantau Island, Tuen Mun and parts of Hong Kong Island. The incessant downpour necessitated the issuance of the Black Rainstorm Warning for the fifth time in the year, breaking the previous annual record of three times set in 2000 and 2006 since the rainstorm warning system began operation in 1992.
The strike of tropical cyclone Tapah on 7 – 8 September
Tapah formed as a tropical depression near Luzon on 5 September. It tracked west-northwestwards across the central and northern parts of the South China Sea on 6 September. Tapah turned north-northwestwards towards the western coast of Guangdong on 7 September and intensified into a severe tropical storm that night. Tapah made landfall near Taishan of Guangdong and then moved into inland Guangxi the next day.
Locally, the weather was mainly cloudy with occasional squally showers and thunderstorms on 7 September. The strike of Tapah necessitated the issuance of the No.8 Gale or Storm Signal that night. Gale force winds prevailed over many places, with winds reaching storm force offshore and on high ground at first on 8 September. The rainbands of Tapah also brought heavy squally showers to the territory. More than 100 millimetres of rainfall were recorded over many places on 8 September.
The second signal No. 10 in a year - the strike of Super Typhoon Ragasa on 23 – 25 September
The warmest October
Under the influence of a stronger than normal upper-air anticyclone covering southern China and the late arrival of cooler air from the north, October 2025 was exceptionally warm in Hong Kong. The monthly mean temperature of 27.4 degrees and monthly mean minimum temperature of 25.6 degrees were both the highest on record for October. Moreover, the monthly mean maximum temperature of 29.9 degrees was the second highest on record. There were also a total of 7 hot nights including 4 consecutive hot nights that started from 16 October, and 4 very hot days in the month, all breaking the respective records for October. In particular, the minimum temperature recorded at the Observatory on 19 October was 28.2 degrees, marking the latest hot night in a year and breaking the previous record of 11 October set in 2017.
A dry November
With the dominance of dry northeast monsoon over southern China for most of the time in the month, the weather of November 2025 was much drier than usual in Hong Kong. The monthly mean relative humidity of 60 percent was 12 percent below the normal of 72 percent and was one of the fourth lowest on record for November. In particular, the relative humidity at the Observatory once fell to 16 percent on 27 November, equalling the lowest on record in November since the establishment of the automatic weather station at the Observatory’s Headquarters in 1984.
The warmest second half year
With well above normal temperatures in September, October and December, the second half of 2025 from July to December was exceptionally warm. The mean maximum temperature of 28.9 degrees and mean temperature of 26.3 degrees were both one of the highest on record for the same period. The mean minimum temperature of 24.3 degrees was one of the second highest on record for the same period.
Notes :
[1] Climatological normals for the reference period of 1961-1990, 1971-2000, 1981-2010 and 1991-2020 are available at: https://www.weather.gov.hk/en/cis/normal.htm. Climatological normals of 1991-2020 are referenced in the text unless otherwise stated.
[2] 'Very hot day' refers to the condition with the daily maximum temperature equal to or higher than 33.0 degrees.
[3] 'Hot night' refers to the condition with the daily minimum temperature equal to or higher than 28.0 degrees.
[4] 'Extremely hot day' refers to the condition with the daily maximum temperature equal to or higher than 35.0 degrees.
[5] 'Cold day' refers to the condition with the daily minimum temperature equal to or lower than 12.0 degrees.
[6] Information on the classification of tropical cyclones is available at: https://www.weather.gov.hk/en/informtc/class.htm
Locally, the weather was mainly cloudy with occasional squally showers and thunderstorms on 7 September. The strike of Tapah necessitated the issuance of the No.8 Gale or Storm Signal that night. Gale force winds prevailed over many places, with winds reaching storm force offshore and on high ground at first on 8 September. The rainbands of Tapah also brought heavy squally showers to the territory. More than 100 millimetres of rainfall were recorded over many places on 8 September.
The second signal No. 10 in a year - the strike of Super Typhoon Ragasa on 23 – 25 September
Ragasa formed over the western North Pacific to the east of the Philippines on 18 September. It moved west-northwestwards on the next three days and intensified progressively into a super typhoon. Ragasa moved across Luzon Strait on 22 September and continued to move across the northern part of the South China Sea the next day, edging closer to the coast of Guangdong. Ragasa skirted about 120 kilometers south of Hong Kong with super typhoon intensity on the morning of 24 September.
The maximum sustained wind of Ragasa was about 230 km/h, making it the second strongest tropical cyclone over the South China Sea since the Observatory’s record began in 1950, on par with Saola in 2023 and Yagi in 2024. The ferocious strike of Ragasa necessitated the issuance of the second Hurricane Signal No. 10 in the year, tying the previous record in 1964. Under the influence of Ragasa’s extensive circulation with fierce winds, storm to hurricane force winds affected many places in Hong Kong on 24 September. The maximum 60-minute mean wind speeds recorded at Waglan Island and Cheung Chau were 133 km/h and 114 km/h respectively. There were also frequent heavy squally showers and more than 200 millimetres of rainfall were generally recorded over the territory on that day.
As the approach of Ragasa coincided with the astronomical high tide, storm surge induced by Ragasa resulted in unusually high water level in many parts of the territory. The sea level at Quarry Bay rose to a maximum of 3.4 metres above Chart Datum, close to the level when Super Typhoon Hato hit Hong Kong in 2017. The fierce winds of Ragasa also triggered overtopping waves, causing flooding in many parts of the coastal areas of Hong Kong. In Hong Kong, at least 101 people were injured during the passage of Ragasa. A woman and her son were swept away by swells at the waterfront of Chai Wan and were later rescued. There were at least 5,062 reports of fallen trees, 24 reports of flooding and five reports of landslides. There were more than 1600 road incident reports, including blockage of roads due to fallen trees, flooding or landslides. There were also 25 incident reports related loosened or damaged signboards and scaffoldings. More than 700 flights were cancelled at the Hong Kong International Airport.
The maximum sustained wind of Ragasa was about 230 km/h, making it the second strongest tropical cyclone over the South China Sea since the Observatory’s record began in 1950, on par with Saola in 2023 and Yagi in 2024. The ferocious strike of Ragasa necessitated the issuance of the second Hurricane Signal No. 10 in the year, tying the previous record in 1964. Under the influence of Ragasa’s extensive circulation with fierce winds, storm to hurricane force winds affected many places in Hong Kong on 24 September. The maximum 60-minute mean wind speeds recorded at Waglan Island and Cheung Chau were 133 km/h and 114 km/h respectively. There were also frequent heavy squally showers and more than 200 millimetres of rainfall were generally recorded over the territory on that day.
As the approach of Ragasa coincided with the astronomical high tide, storm surge induced by Ragasa resulted in unusually high water level in many parts of the territory. The sea level at Quarry Bay rose to a maximum of 3.4 metres above Chart Datum, close to the level when Super Typhoon Hato hit Hong Kong in 2017. The fierce winds of Ragasa also triggered overtopping waves, causing flooding in many parts of the coastal areas of Hong Kong. In Hong Kong, at least 101 people were injured during the passage of Ragasa. A woman and her son were swept away by swells at the waterfront of Chai Wan and were later rescued. There were at least 5,062 reports of fallen trees, 24 reports of flooding and five reports of landslides. There were more than 1600 road incident reports, including blockage of roads due to fallen trees, flooding or landslides. There were also 25 incident reports related loosened or damaged signboards and scaffoldings. More than 700 flights were cancelled at the Hong Kong International Airport.
Fig. 14 – 17 The passage of Super Typhoon Ragasa caused extensive damage over many parts of Hong Kong, including fallen trees, overtopping waves, storm surge and landslides (Courtesy of Highways Department, Kwok Yung Chan/CWOS, YW Lee, and the Head of the Geotechnical Engineering Office and the Director of the Civil Engineering and Development (from top to bottom))
The warmest October
Under the influence of a stronger than normal upper-air anticyclone covering southern China and the late arrival of cooler air from the north, October 2025 was exceptionally warm in Hong Kong. The monthly mean temperature of 27.4 degrees and monthly mean minimum temperature of 25.6 degrees were both the highest on record for October. Moreover, the monthly mean maximum temperature of 29.9 degrees was the second highest on record. There were also a total of 7 hot nights including 4 consecutive hot nights that started from 16 October, and 4 very hot days in the month, all breaking the respective records for October. In particular, the minimum temperature recorded at the Observatory on 19 October was 28.2 degrees, marking the latest hot night in a year and breaking the previous record of 11 October set in 2017.
A dry November
With the dominance of dry northeast monsoon over southern China for most of the time in the month, the weather of November 2025 was much drier than usual in Hong Kong. The monthly mean relative humidity of 60 percent was 12 percent below the normal of 72 percent and was one of the fourth lowest on record for November. In particular, the relative humidity at the Observatory once fell to 16 percent on 27 November, equalling the lowest on record in November since the establishment of the automatic weather station at the Observatory’s Headquarters in 1984.
The warmest second half year
With well above normal temperatures in September, October and December, the second half of 2025 from July to December was exceptionally warm. The mean maximum temperature of 28.9 degrees and mean temperature of 26.3 degrees were both one of the highest on record for the same period. The mean minimum temperature of 24.3 degrees was one of the second highest on record for the same period.
Notes :
[1] Climatological normals for the reference period of 1961-1990, 1971-2000, 1981-2010 and 1991-2020 are available at: https://www.weather.gov.hk/en/cis/normal.htm. Climatological normals of 1991-2020 are referenced in the text unless otherwise stated.
[2] 'Very hot day' refers to the condition with the daily maximum temperature equal to or higher than 33.0 degrees.
[3] 'Hot night' refers to the condition with the daily minimum temperature equal to or higher than 28.0 degrees.
[4] 'Extremely hot day' refers to the condition with the daily maximum temperature equal to or higher than 35.0 degrees.
[5] 'Cold day' refers to the condition with the daily minimum temperature equal to or lower than 12.0 degrees.
[6] Information on the classification of tropical cyclones is available at: https://www.weather.gov.hk/en/informtc/class.htm
Table 1 Summary of record-breaking events in 2025
| Record-breaking Events (since records began in 1884, unless otherwise specified) |
Date / Period | New Record |
| 1. Lowest absolute minimum relative humidity for April (since the establishment of the automatic weather station at the Observatory's Headquarters in 1984) | 13 April 2025 | 21% |
| 2. Earliest occurrence of very hot day in a year | 15 April 2025 | 15 April |
| 3. Highest daily maximum temperature for Easter (on par with 5 April 2015) | 20 April 2025 | 30.6°C |
| 4. Lowest seasonal mean relative humidity for spring (since 1947) | March to May 2025 | 75% |
| 5. Highest absolute maximum temperature for June (on par with 1 June 1963) | 10 June 2025 | 35.6°C |
| 6. Highest daily maximum temperature for Moderate Heat | 7 July 2025 | 34.3°C |
| 7. Highest daily total rainfall for August | 5 August 2025 | 368.9 mm |
| 8. Highest number of very hot days for September (on par with September 2021) | September 2025 | 15 days |
| 9. Highest number of hot nights for September | September 2025 | 13 days |
| 10. Highest monthly mean temperature for October | October 2025 | 27.4°C |
| 11. Highest monthly mean minimum temperature for October | October 2025 | 25.6°C |
| 12. Highest number of hot nights for October | October 2025 | 7 days |
| 13. Highest number of consecutive hot nights for October | 16 – 19 October 2025 | 4 days |
| 14. Highest number of very hot days for October | October 2025 | 4 days |
| 15. Highest daily maximum temperature for Cold Dew | 8 October 2025 | 33.1°C |
| 16. Latest occurrence of hot night in a year | 19 October 2025 | 19 October |
| 17. Lowest absolute minimum relative humidity for November (since the establishment of the automatic weather station at the Observatory's Headquarters in 1984) (on par with 24 November 1995) | 27 November 2025 | 16% |
| 18. Highest mean maximum temperature for the second half of the year (on par with second half of 2019, 2023 and 2024) | July to December 2025 | 28.9°C |
| 19. Highest mean temperature for the second half of the year (on par with second half of 2024) | July to December 2025 | 26.3°C |
| 20. Lowest annual mean relative humidity (on par with 1963 since 1947) | 2025 | 73% |
 Month |
Mean Pressure (hPa) |
Air Temperature | Mean Dew Point (deg. C) |
Mean Relative Humidity (%) |
Mean Amount of Cloud (%) |
Total Rainfall (mm) |
||
|---|---|---|---|---|---|---|---|---|
Mean Daily Maximum (deg. C) |
Mean (deg. C) |
Mean Daily Minimum (deg. C) |
||||||
| January | 1020.6 | 19.8 | 17.1 | 15.0 | 8.5 | 59 | 44 | 4.2 |
| February | 1020.5 | 19.9 | 17.3 | 15.3 | 12.1 | 73 | 72 | 26.1 |
| March | 1016.7 | 23.5 | 20.1 | 17.7 | 15.0 | 74 | 66 | 38.1 |
| April | 1013.0 | 26.7 | 23.7 | 21.6 | 18.3 | 74 | 71 | 57.1 |
| May | 1010.1 | 30.0 | 27.2 | 25.5 | 22.6 | 77 | 81 | 81.6 |
| June | 1006.7 | 31.5 | 28.9 | 27.1 | 25.1 | 80 | 83 | 237.3 |
| July | 1001.3 | 32.4 | 29.5 | 27.4 | 25.7 | 81 | 80 | 601.7 |
| August | 1007.8 | 31.7 | 29.0 | 27.0 | 25.2 | 81 | 81 | 939.2 |
| September | 1008.7 | 32.2 | 29.3 | 27.3 | 24.8 | 77 | 73 | 528.7 |
| October | 1013.8 | 29.9 | 27.4 | 25.6 | 21.7 | 72 | 66 | 31.2 |
| November | 1017.3 | 24.7 | 22.3 | 20.3 | 13.8 | 60 | 72 | 7.0 |
| December | 1018.5 | 22.4 | 20.2 | 18.4 | 14.4 | 70 | 58 | 6.5 |
| Mean/Total | 1012.9 | 27.1 | 24.3 | 22.4 | 18.9 | 73 | 71 | 2558.7 |
| Normal(1991-2020) | 1012.9 | 26.0 | 23.5 | 21.6 | 19.3 | 78 | 68 | 2431.2 |
| Station | Hong Kong Observatory | |||||||
Trace means rainfall less than 0.05 mm
Table 2b Summary of meteorological observations in Hong Kong, 2025
Month |
Number of hours of Reduced Visibility# (hours) |
Total Bright Sunshine (hours) |
Mean Daily Global Solar Radiation (MJ/m2) |
Total Evaporation (mm) |
Prevailing Wind Direction (degrees) |
Mean Wind Speed (km/h) |
|
|---|---|---|---|---|---|---|---|
| January | 6 | 2 | 222.3 | 14.82 | 101.3 | 060 | 23.9 |
| February | 55 | 18 | 113.1 | 12.55 | 74.0 | 060 | 24.6 |
| March | 28 | 0 | 130.6 | 13.84 | 89.9 | 010 | 17.3 |
| April | 73 | 0 | 155.6 | 15.75 | 104.3 | 050 | 15.6 |
| May | 49 | 0 | 123.2 | 15.28 | 116.0 | 070 | 16.5 |
| June | 7 | 0 | 144.9 | 16.62 | 91.7 | 080 | 20.0 |
| July | 2 | 0 | 191.9 | 15.28 | 117.9 | 240 | 20.6 |
| August | 1 | 0 | 174.0 | 15.29 | 107.0 | 080 | 20.6 |
| September | 0 | 0 | 194.5 | 16.71 | 115.9 | 080 | 21.5 |
| October | 1 | 0 | 189.3 | 15.25 | 120.4 | 080 | 23.7 |
| November | 3 | 0 | 173.8 | 13.21 | 105.6 | 360 | 28.5 |
| December | 41 | 12 | 166.0 | 11.86 | 76.5 | 070 | 21.2 |
| Mean/Total | 266 | 32 | 1979.2 | 14.71 | 1220.5 | 070 | 21.2 |
| Normal(1991-2020) | 825.8 | 974.2§ | 1829.3 | 13.23 | 1204.1 | 070 | 22.9 |
| Station | Hong Kong Observatory |
Hong Kong International Airport |
King's Park | Waglan Island | |||
# Visibility below 8 km when there is no fog, mist, or precipitation
§ 1997-2024 Mean value
Table 2c Summary of meteorological observations in Hong Kong, 2025
Month |
Number of Extremely Hot Days |
Number of Very Hot Days |
Number of Hot Nights |
Number of Cold Days |
Number of Days with Thunderstorms |
|---|---|---|---|---|---|
| January | - | - | - | 4 | - |
| February | - | - | - | 2 | - |
| March | - | - | - | - | 1 |
| April | - | 1 | - | - | 1 |
| May | - | 1 | 3 | - | 2 |
| June | 1 | 6 | 8 | - | 7 |
| July | 1 | 17 | 13 | - | 10 |
| August | - | 9 | 10 | - | 8 |
| September | 2 | 15 | 13 | - | 7 |
| October | - | 4 | 7 | - | 1 |
| November | - | - | - | - | - |
| December | - | - | - | - | - |
| Total | 4 | 53 | 54 | 6 | 37 |
| Normal(1991-2020) | 0.8 | 17.5 | 23.6 | 15.2 | 42.3 |
| Station | Hong Kong Observatory | ||||