Ocean State Report 10 reveals two-decade high in Mediterranean marine heatwaves
On 30 September 2026, the Copernicus Marine Service released the 10th edition of the Copernicus Ocean State Report (OSR10), marking a decade of monitoring and documenting changes in the ocean. Among the report’s key findings is the record marine heatwave activity in the Mediterranean Sea in 2024. In 2024 the Mediterranean recorded the highest number of marine heatwave days in the past two decades, while average sea surface temperatures reached 1.23°C above the 1982–2024 baseline. Conditions were most extreme in the eastern Mediterranean, where the highest number of marine heatwaves, the longest average duration, and the strongest intensity of the past two decades were registered.
This data visualisation shows the long-term trend in sea surface temperature across the Mediterranean from 1982 to 2024. Over this period, the average sea surface temperature across the basin increased by 0.32 ± 0.01°C per decade, although the rate of warming varied from one area to another.
The full findings are available in the Copernicus Ocean State Report 10, which provides a comprehensive, science-based overview of the state and evolution of the global ocean.
