State of the climate: Update for COP30

This report is a science-based reference to anchor COP 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. The report also provides a snapshot of how the World Meteorological Organization (WMO) community is supporting decision-makers with weather and climate intelligence. One of the report's main findings is that the alarming streak of exceptional temperatures continued in 2025, which is set to be either the second or third warmest year on record.

The report highlights that the past 11 years, 2015 to 2025, will individually have been the eleven warmest years in the 176-year observational record, with the past three years being the three warmest years on record. The mean near-surface temperature in January-August 2025 was 1.42 °C ± 0.12 °C above the pre-industrial average. 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.