The South-West Pacific experienced its second warmest year on record in 2025, as rising ocean temperatures, marine heatwaves and sea-level rise intensified climate risks across the region, according to a new report released by the World Meteorological Organization (WMO) on Monday.

The State of the Climate in the South-West Pacific 2025 report found that warming oceans and increasingly frequent marine heatwaves disrupted marine ecosystems, fisheries and coastal communities. The findings were released during the Southeast Asia Marine Heatwaves Services Workshop in Singapore, where scientists and policymakers discussed ways to strengthen climate resilience and improve early warning systems.

Marine Heatwaves Threaten Fisheries And Coastal Communities

According to the WMO, the South-West Pacific recorded its second warmest year on record, with the annual average surface air temperature reaching 0.37 degrees Celsius above the 1991–2020 average. While La Niña conditions temporarily cooled parts of the central tropical Pacific, overall ocean temperatures across the region remained exceptionally high.

The report said record ocean heat content was observed south of Australia, in the southern Tasman Sea, and in parts of the tropical North Pacific between the Philippines and Hawaii. Marine heatwaves have become more frequent, longer-lasting and more intense due to long-term ocean warming. Scientists said these events are causing widespread coral bleaching, fish mortality, harmful algal blooms, shifts in marine species and significant losses for fisheries and aquaculture.

Glacier Loss And Extreme Weather Highlight Climate Impacts

The report also warned that Indonesia's last remaining tropical glacier in Papua has shrunk to about 2% of its 1988 extent and is expected to disappear by the end of 2026 or early 2027 if current trends continue.

Extreme weather also had severe humanitarian consequences during 2025. According to the WMO, Cyclone Senyar, the first known tropical cyclone to reach cyclone intensity in the Strait of Malacca, affected more than 10 million people in Indonesia and Malaysia and caused more than 1,200 deaths, making it the region's deadliest weather disaster of the year.

Early Warning Systems Remain A Priority

WMO Secretary-General, Celeste Saulo, said the ocean remains central to livelihoods, economies and resilience across the South-West Pacific, but warming oceans, rising sea levels, ocean acidification and tropical cyclones are increasing climate-related risks.

The report highlighted that effective early warning systems and timely early action continue to save lives. However, it said important gaps remain in forecasting capacity, coordination and last-mile communication, particularly for vulnerable communities. The WMO said expanding marine heatwave forecasting services could provide governments, fisheries and coastal industries with weeks or months of advance notice to prepare for climate-related impacts.