The European Union’s climate monitoring service says ocean sea surface temperatures are approaching all-time highs as conditions transition toward El Niño. Samantha Burgess of the European Centre for Medium-Range Weather Forecasts (ECMWF) tells AFP that recent sea surface temperatures are just below the all-time highs recorded in 2024 and that May may set a new record. The Copernicus Climate Change Service, which is run with ECMWF involvement, reports that daily sea surface temperatures in April steadily rose toward near-record levels.

Copernicus says April was the second-warmest measured globally for sea surface temperatures and that marine heatwaves set records in parts of the Pacific between the tropics and the United States. It also links the warming to an observed shift from neutral conditions toward El Niño during March and April. The World Meteorological Organization has said El Niño conditions could emerge between May and July.

Multiple sources note that El Niño can influence global weather and increase the likelihood of drought, heavy rainfall, and other extremes, while long-term warming driven by greenhouse gas emissions also leaves the ocean system more prone to record-level heat. Scientists caution that forecasts of El Niño’s strength remain uncertain, but impacts typically peak in the year after it develops.