Extreme heat and rainfall, glacier loss and record ocean heat impact Asia in 2025

The WMO State of the Climate in Asia 2025 reports that ocean heat, which has increased since the 1990s, reached a new record. Marine heatwaves affected almost the entire ocean area of Asia, with over 10 million km2 impacted during July–September – more than the size of People’s Republic of China or the United States of America. Continued ocean warming and acidification pose increasing risks to marine ecosystems and coastal communities.

All 23 monitored glaciers in High-mountain Asia lost mass, driven by above-average temperatures and below-average winter snow. This threatens long-term water security in the world’s most heavily populated region and leads to an upsurge in hazards – with multiple glacial lake outburst floods and glacier collapses being recorded in 2025.

Asia has warmed faster than the global average in recent decades, with the warming trend during 1991–2025 approximately twice that observed during 1961–1990. The year 2025 was between the second and fourth warmest year on record depending on the dataset used.

Extreme heat was a defining feature, with Japan, People’s Republic of China and the Republic of Korea all recording their hottest summer on record. Exceptional monsoon and tropical cyclone-related rainfall caused devastating flooding in many countries, including Pakistan, Sri Lanka and Viet Nam. Stubborn drought hit parts of West Asia, including the Islamic Republic of Iran, as did severe sand and dust storms.

“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. This report highlights the importance of observations, early warning systems and impact-based forecasting to adapt to our changing climate,” said WMO Secretary-General Celeste Saulo.

“Across Asia and the Pacific, heat is intensifying multi-hazard risks, intersecting with food systems, public health, infrastructure and oceans and placing new pressures on health and livelihoods. Early warning and early action save lives when alerts are timely, messages are trusted and last-mile delivery reaches the vulnerable. Resilience is built over time, through a sustained culture of preparedness,” said Armida Salsiah Alisjahbana, Under-Secretary-General of the United Nations and Executive Secretary of the Economic and Social Commission for Asia and the Pacific (ESCAP).

The State of the Climate in Asia 2025 provides authoritative information on key climate indicators, major extreme events, impacts and risks. It includes case studies which demonstrate the scale of the risk and the need to strengthen impact-based forecasting and preparedness on what the weather will DO, rather than simply what it will BE.

The report incorporates input from dozens of experts, National Meteorological and Hydrological Services, climate monitoring centres and United Nations partners. It is one of a series of WMO regional reports to inform decision-making.