Sea surface temperatures reach historic records this June

• Both in the Mediterranean and the Cantabrian Sea, record-high sea surface temperatures for the month of June have been registered: 26.2ºC in Pasaia and 30.55ºC in Dragonera.
• Puertos del Estado receives real-time data from its monitoring networks and manages and distributes information on sea temperature and other variables such as waves and currents.

02-07-2025 (Puertos del Estado). Sea surface temperatures have reached new records this June, exceeding the historical maximum values recorded for the same month, according to data from the Puertos del Estado buoy network.

The highest sea surface temperature recorded in June was 30.55ºC, measured by the Dragonera buoy on 30 June at 15:00 UTC (17:00 local time).

Graph showing the time series of water temperature measured by the Dragonera Buoy from 1 to 30 June 2025. The record value for June is highlighted, which is also the highest sea surface temperature measured in June by the Puertos del Estado buoy network. All times shown are in UTC.

This same buoy, part of the Deep-Water Buoy Network, holds the all-time sea temperature record with 31.87ºC, recorded in August 2024.

Within the Deep-Water Network, individual monthly records for June have been set across all buoys deployed in the Mediterranean. Notably, the Cabo Begur buoy matched its historical maximum with 29.1ºC, measured on 30 June at 13:00 UTC (15:00 local time).
In the Atlantic, the Bilbao-Vizcaya buoy recorded 23.93ºC, and the Villano-Sisargas buoy reached 19.99ºC, both records for the month of June, measured on 30 June at 18:00 UTC (20:00 local time). The Cabo de Peñas buoy also marked a new June maximum with 20.97ºC recorded on 27 June.

Graph showing the time series of water temperature measured by the Cabo Begur Buoy during June 2025, when it matched its historical maximum.

Meanwhile, the Coastal Buoy Network, located closer to ports and beaches, also recorded unprecedented sea temperatures for June in the Mediterranean. Highlights include 28.8ºC, measured by the Tarragona coastal buoy on 29 June at 15:00 UTC (17:00 local time), and 27.6ºC recorded by the Barcelona buoy on 30 June at the same time.
In the Atlantic basin, record-high June temperatures were also observed in recent days, including 26.2ºC at the Pasaia buoy on 30 June and 23.4ºC at the Bilbao buoy on 20 June.

PUERTOS DEL ESTADO MONITORING NETWORKS
Puertos del Estado operates a Deep-Water Buoy Network with 15 monitoring stations, a Coastal Buoy Network with 12 stations, a network of 46 tide gauges along the Spanish coastline, and a High-Frequency Radar Network comprising 9 stations, jointly managed with other institutions. All data are received in real time by Puertos del Estado, which is responsible for managing and distributing the information.
https://portus.puertos.es/

Image from the Portus website of Puertos del Estado for 29 June 2025. The map shows the daily average sea surface temperature based on Sentinel-3 satellite data. This product is developed by the Remote Sensing Systems Department of INTA within the framework of the Copernicus STERNA project.