Overview
- National analyses from NOAA’s NCEI and the EU’s Copernicus show May 2026 ranked second-highest in the instrumental record with global surface temperatures well above long-term averages and ocean temperatures near record levels.
- The World Meteorological Organization assesses about an 80% chance of El Niño forming in June–August and roughly a 90% chance it will persist into November, raising the probability that 2026 will be one of the warmest years on record.
- Western Europe experienced an unusually early and intense heatwave in late May that broke numerous monthly records across the United Kingdom, France, Ireland and Portugal and created widespread heat stress.
- Other climate signals were mixed but notable: Arctic and Antarctic sea ice and Northern Hemisphere snow cover were well below average for May while global tropical cyclone activity was lower than normal, with only two named storms.
- Authorities warn the likely El Niño could increase the risk of heatwaves, droughts and heavy rainfall that would harm crops, water supplies and vulnerable communities, and they urge strengthened monitoring, forecasting and early warnings.