Asia warming nearly twice as fast as before, 2025 among hottest years: UN weather body
The report highlights record ocean heat, widespread marine heatwaves, accelerating glacier loss and a series of extreme weather events that caused significant human and economic losses across Asia.
Asia’s warming rate during 1991-2025 was nearly twice as high as during 1961-1990, with 2025 emerging as one of the region’s warmest years on record and witnessing unprecedented ocean heat that triggered widespread marine heatwaves, according to the World Meteorological Organization (WMO).
WMO’s State of the Climate in Asia 2025 report, released Wednesday, found that temperatures over the Asian landmass in 2025 were 0.96 degree Celsius above the 1991-2020 average and about 1.9 degree Celsius higher than the 1961-1990 baseline. While temperatures were above average across most of Asia, parts of South Asia, including the Indian subcontinent, experienced relatively cooler conditions due to favourable monsoon rainfall.
“Temperatures were above average across most of the region, except for parts of South Asia. Cooler than average conditions prevailed over South Asia, including the Indian sub-continent, mainly due to good rainfall during the monsoon season,” the report said.
“A pronounced warming trend has emerged across Asia since the latter half of the twentieth century. During the two most recent subperiods (1961-1990 and 1991-2025), Asia warmed more rapidly than the global land and ocean average,” the report said.
“This pattern is consistent with findings from the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, which also notes that temperatures over land increase faster than those over the ocean. Notably, the warming trend in Asia during the 1991-2025 period was approximately twice as strong as observed in the region during the 1991-1960 period,” it added.
Extreme weather events
The report highlighted a range of climate-related impacts across the continent, including glacial lake outburst floods, record summer heat in East Asia, drought in West Asia, and tropical cyclones accompanied by severe flooding in South and Southeast Asia. India experienced flash floods in the Uttarkashi district of Uttarakhand, while the effects of Cyclone Ditwah, which devastated Sri Lanka, also led to flooding in parts of Tamil Nadu.
Extreme weather events inflicted significant economic and human losses. Vietnam recorded losses estimated at $1.9 billion due to prolonged flooding, while Sri Lanka suffered 640 deaths, large-scale displacement, and economic losses equivalent to about 4 per cent of its GDP following Cyclone Ditwah and associated floods.
“Asia is impacted by rising temperatures, warming ocean waters, higher sea levels and retreating glaciers. Heavy rainfall, flooding and drought have a heavy economic and human cost, while extreme heat, dust storms and glacial flooding are becoming major hazards,” said Celeste Saulo, Secretary-General, WMO.
Ocean warming
One of the report’s key findings was the record-high ocean heat content across Asia in 2025, the highest since observations began in 1960. Particularly intense subsurface ocean warming was observed in the south-eastern Arabian Sea, the southern Bay of Bengal, waters south of Sri Lanka extending into the central equatorial Indian Ocean, and parts of the North Pacific.
Ocean heat is a critical climate indicator because nearly 90 per cent of the excess energy trapped by greenhouse gases is absorbed by the oceans, altering temperatures at different depths and contributing to sea-level rise and changes in ocean circulation patterns.
The report also found that almost all of Asia’s ocean area experienced marine heatwaves of strong, severe, or extreme intensity during 2025. The most affected regions included the northern Indian Ocean, waters around Japan, the Yellow Sea, and the East China Sea. Such heatwaves can severely affect marine ecosystems and communities dependent on fisheries and coastal livelihoods.
Heat waves
Several countries in East Asia recorded unprecedented heat. Japan, China, and the Republic of Korea all experienced their hottest summers on record. In Japan, average summer temperatures were 2.36 degrees Celsius above the 1991-2020 average, exceeding the previous records set in 2023 and 2024. Central Asia also witnessed prolonged heatwaves during spring and summer, with parts of Kazakhstan recording daily temperature anomalies of up to 14 degrees Celsius above normal.
The warming trend continued to accelerate glacier loss in the High Mountain Asia region, which includes the Tibetan Plateau and contains the largest volume of ice outside the polar regions. All 23 monitored glaciers in the region lost mass in 2025 due to below-average winter snowfall and persistently high temperatures from May to September.
The report also noted that oceans and seas across Asia have continued warming since the 1990s. Sea levels reached record highs in 2025, while both the Arabian Sea and Bay of Bengal registered declining pH levels, indicating increasing ocean acidification.
Asia’s warming rate during 1991-2025 was nearly twice as high as during 1961-1990, with 2025 emerging as one of the region’s warmest years on record and witnessing unprecedented ocean heat that triggered widespread marine heatwaves, according to the World Meteorological Organization (WMO).
WMO’s State of the Climate in Asia 2025 report, released Wednesday, found that temperatures over the Asian landmass in 2025 were 0.96 degree Celsius above the 1991-2020 average and about 1.9 degree Celsius higher than the 1961-1990 baseline. While temperatures were above average across most of Asia, parts of South Asia, including the Indian subcontinent, experienced relatively cooler conditions due to favourable monsoon rainfall.
“Temperatures were above average across most of the region, except for parts of South Asia. Cooler than average conditions prevailed over South Asia, including the Indian sub-continent, mainly due to good rainfall during the monsoon season,” the report said.
“A pronounced warming trend has emerged across Asia since the latter half of the twentieth century. During the two most recent subperiods (1961-1990 and 1991-2025), Asia warmed more rapidly than the global land and ocean average,” the report said.
“This pattern is consistent with findings from the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report, which also notes that temperatures over land increase faster than those over the ocean. Notably, the warming trend in Asia during the 1991-2025 period was approximately twice as strong as observed in the region during the 1991-1960 period,” it added.
Extreme weather events
The report highlighted a range of climate-related impacts across the continent, including glacial lake outburst floods, record summer heat in East Asia, drought in West Asia, and tropical cyclones accompanied by severe flooding in South and Southeast Asia. India experienced flash floods in the Uttarkashi district of Uttarakhand, while the effects of Cyclone Ditwah, which devastated Sri Lanka, also led to flooding in parts of Tamil Nadu.
Extreme weather events inflicted significant economic and human losses. Vietnam recorded losses estimated at $1.9 billion due to prolonged flooding, while Sri Lanka suffered 640 deaths, large-scale displacement, and economic losses equivalent to about 4 per cent of its GDP following Cyclone Ditwah and associated floods.
“Asia is impacted by rising temperatures, warming ocean waters, higher sea levels and retreating glaciers. Heavy rainfall, flooding and drought have a heavy economic and human cost, while extreme heat, dust storms and glacial flooding are becoming major hazards,” said Celeste Saulo, Secretary-General, WMO.
Ocean warming
One of the report’s key findings was the record-high ocean heat content across Asia in 2025, the highest since observations began in 1960. Particularly intense subsurface ocean warming was observed in the south-eastern Arabian Sea, the southern Bay of Bengal, waters south of Sri Lanka extending into the central equatorial Indian Ocean, and parts of the North Pacific.
Ocean heat is a critical climate indicator because nearly 90 per cent of the excess energy trapped by greenhouse gases is absorbed by the oceans, altering temperatures at different depths and contributing to sea-level rise and changes in ocean circulation patterns.
The report also found that almost all of Asia’s ocean area experienced marine heatwaves of strong, severe, or extreme intensity during 2025. The most affected regions included the northern Indian Ocean, waters around Japan, the Yellow Sea, and the East China Sea. Such heatwaves can severely affect marine ecosystems and communities dependent on fisheries and coastal livelihoods.
Heat waves
Several countries in East Asia recorded unprecedented heat. Japan, China, and the Republic of Korea all experienced their hottest summers on record. In Japan, average summer temperatures were 2.36 degrees Celsius above the 1991-2020 average, exceeding the previous records set in 2023 and 2024. Central Asia also witnessed prolonged heatwaves during spring and summer, with parts of Kazakhstan recording daily temperature anomalies of up to 14 degrees Celsius above normal.
The warming trend continued to accelerate glacier loss in the High Mountain Asia region, which includes the Tibetan Plateau and contains the largest volume of ice outside the polar regions. All 23 monitored glaciers in the region lost mass in 2025 due to below-average winter snowfall and persistently high temperatures from May to September.
The report also noted that oceans and seas across Asia have continued warming since the 1990s. Sea levels reached record highs in 2025, while both the Arabian Sea and Bay of Bengal registered declining pH levels, indicating increasing ocean acidification.
