Overview
- Copernicus reported on 21 June that global sea‑surface temperatures reached a June record of about 20.86–21.0 °C, a finding supported by the University of Maine’s ClimateReanalyzer (~20.97 °C).
- International agencies including NASA, WMO and NOAA say El Niño has returned and NASA scientists warn satellite data from Sentinel‑6 show large warm‑water waves and subsurface heat that could strengthen the event.
- Warmer oceans store roughly 90% of excess heat from greenhouse gases, which raises atmospheric energy, fuels stronger storms and increases the chance of heavy rainfall and flooding.
- Certain regions are already far above normal temperatures, with reports of about 28 °C near Sardinia that raise short‑term risks of local heatwaves, severe storms and stress to fisheries and coastal communities.
- Copernicus notes sea‑surface temperatures outside polar regions have been about 0.35–0.73 °C above long‑term averages over the past three years and warns more temperature records and marine heatwaves are likely in coming months.