Swimming in hot water: Mediterranean Sea experiencing ongoing heatwave

If it already feels like you are swimming in hot water at the beach there is nothing wrong with your internal thermostat.

For sure, the summer is now with us but the normally high sea surface temperatures are even higher than usual since the Mediterranean Sea is experiencing a marine heatwave.

This phenomenon is ongoing with the most intense warming observed along the Spanish and French coastlines, satellite data collected by Copernicus shows.

An image disseminated by Copernicus visualises sea surface temperatures in the Mediterranean and shows anomalies recorded on 22 June 2025.

Areas in dark red indicate temperatures more than 5°C above the seasonal average. The most intense warming was observed in the western Mediterranean basin, including the Balearic Sea and the Tyrrhenian Sea.

The visualisation is based on Copernicus Marine Service data. Copernicus is the earth observation component of the EU’s Space programme.

Meanwhile, according to Mercator Ocean International, an information service, the marine heatwave in the Mediterranean is increasing in “both extent and intensity”. The organisation noted the emergence of “severe categories” off the southeastern coast of Spain.