The World Meteorological Organization’s State of the Climate Update for COP30 reveals that the past 11 years (2015-2025) are set to be the warmest on record, with each year surpassing previous temperature highs. The global mean temperature for January-August 2025 was 1.42 °C ‡ 0.12 °C above pre-industrial levels, underscoring the accelerating pace of climate change.

Concentrations of heat-trapping greenhouse gases and ocean heat content, which both reached record levels in 2024, continued to rise in 2025. Arctic sea ice extent after the winter freeze was the lowest on record, and Antarctic sea ice extent tracked well below average throughout the year. The long-term sea level rise trend continued despite a small and temporary blip due to naturally occurring factors.

Weather and climate-related extreme events to August 2025 – ranging from devastating rainfall and flooding to brutal heat and wildfires – had cascading impacts on lives, livelihoods and food systems. This contributed to displacement across multiple regions, undermining sustainable development and economic progress.

WMO released the State of the Global Climate Update for COP30 at the Leaders’ Summit of the UN Climate Change Conference in Belém, Brazil. The report was launched by WMO Secretary-General Prof. Celeste Saulo as a science-based reference to anchor COP30 negotiations in authoritative evidence. It highlights key climate indicators and their relevance to support policymaking and is a bridge to more detailed but less frequent scientific reports.