Asia's Warming Rate Nearly Doubles, 2025 Among Hottest Years on Record

Asia's warming rate between 1991 and 2025 was nearly double that of the 1961-1990 period, with 2025 emerging as one of the region's hottest years on record, according to the World Meteorological Organization (WMO). The year also saw unprecedented ocean heat, triggering widespread marine heatwaves across the continent.

The WMO’s State of the Climate in Asia 2025 report, released on Wednesday, revealed that temperatures over the Asian landmass in 2025 were 0.96°C above the 1991-2020 average and approximately 1.9°C higher than the 1961-1990 baseline. While most of Asia experienced above-average temperatures, parts of South Asia, including the Indian subcontinent, recorded cooler conditions due to favorable monsoon rainfall.

The report underscored a pronounced warming trend across Asia since the latter half of the 20th century. During the 1991-2025 period, the region warmed at nearly twice the rate observed during 1961-1990. This trend aligns with findings from the Intergovernmental Panel on sustainability-advocacy Climate Change (IPCC), which highlights that land areas warm faster than oceans.

Extreme Weather Events and Economic Losses

Asia faced a range of climate-related impacts in 2025, including glacial lake outburst floods, record summer heat in East Asia, drought in West Asia, and tropical cyclones that caused severe flooding in South and Southeast Asia.

India experienced flash floods in Uttarakhand’s Uttarkashi district, while Cyclone Ditwah, which devastated Sri Lanka, also caused flooding in Tamil Nadu. These events led to significant economic and human losses.

Vietnam suffered $1.9 billion in damages from prolonged flooding, while Sri Lanka recorded 640 deaths, large-scale displacement, and economic losses equivalent to 4% of its GDP due to 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 carry heavy economic and human costs, while extreme heat, dust storms, and glacial flooding are becoming major hazards,” said WMO Secretary-General Celeste Saulo.

Record Ocean Heat and Marine Heatwaves

The report highlighted record-high ocean heat content across Asia in 2025, the highest since observations began in 1960. Intense subsurface warming was observed in the southeastern Arabian Sea, southern Bay of Bengal, waters south of Sri Lanka, the central equatorial Indian Ocean, and parts of the North Pacific.

Nearly all of Asia’s ocean areas experienced marine heatwaves of strong, severe, or extreme intensity in 2025. The most affected regions included the northern Indian Ocean, waters around Japan, the Yellow Sea, and the East China Sea. These heatwaves pose significant risks to marine ecosystems and communities reliant on fisheries and coastal livelihoods.

Heatwaves and Glacier Loss

Several East Asian countries, including Japan, China, and the Republic of Korea, recorded their hottest summers on record in 2025. Japan’s average summer temperatures were 2.36°C above the 1991-2020 average, surpassing previous records set in 2023 and 2024. Central Asia also experienced prolonged heatwaves, with parts of Kazakhstan recording daily temperature anomalies up to 14°C above normal.

The warming trend has accelerated glacier loss in the High Mountain Asia region, which includes the Tibetan Plateau. 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.

Rising Sea Levels and Ocean Acidification

Sea levels across Asia reached record highs in 2025, while both the Arabian Sea and Bay of Bengal experienced declining pH levels, indicating increased ocean acidification. These changes further highlight the ongoing impacts of climate change on the region’s oceans and ecosystems.

The findings underscore the urgent need for climate action as Asia continues to grapple with the accelerating impacts of global warming. [S1-S13]