Spanish waters reach 'record highs' in May after extreme heat

State Ports network buoys logged record May sea temperatures at 18 of 29 stations, from Galicia and the Cantabrian coast to the Mediterranean, peaking at 26.58°C off Mahón. From the Cantabrian coast to the Balearic Islands, Spanish waters ended May with temperatures never before seen at this time of year. Measurements by Puertos del Estado show record highs for this month along much of the coastline, after an episode of exceptional heat that also sent temperatures soaring on land. According to the public body (source in Spanish), sea water temperatures reached new records in May, exceeding the previous maximum values recorded for this month. In total, 18 of the 29 buoys in its network registered exceptionally high temperatures. Specifically, 12 of the 15 buoys in the Offshore Network and 6 of the 14 in the Coastal Network recorded their highest values since their respective data series began. The records were spread across much of the Spanish coastline. All the buoys located off Galicia and in the Cantabrian Sea registered all-time highs, as did numerous stations in the Mediterranean. Record highs in the Balearics The highest value in the entire network was recorded by the buoy at Mahón, on Menorca, which reached 26.58 degrees on 27 May. It was followed by the Dragonera buoy, also in the Balearics, with 26.2 degrees on the 30th. Other stations that broke monthly records included Tarragona, with 24.64 degrees; Cabo Begur, with 24.47 degrees; and Valencia, with 23.47 degrees. The Coastal Buoy Network also recorded unprecedented temperatures for May. Particularly notable were the 24.5 degrees measured in Tarragona on 30 May and the 24.2 degrees registered in Barcelona the following day. Record highs for this month were also reached at the stations in Bilbao, Pasaia, Gijón and Langosteira. Among the deep-water buoys that set new records were those at Bilbao–Vizcaya, Cabo de Peñas, Estaca de Bares, Villano–Sisargas, Cabo Silleiro, Valencia, Tarragona, Cabo Begur, Dragonera and Mahón, according to data released by Puertos del Estado. A sea warmer than usual These readings coincide with a spell of exceptional heat that affected Spain and much of Europe during the second half of May. According to the State Meteorological Agency (AEMET), some areas recorded temperatures more typical of summer than of late spring, while in the Cantabrian Sea surface temperatures were between 1.5 and 2 degrees above the usual values for this time of year. Experts point out that the ocean responds more slowly to atmospheric changes because of its high thermal inertia. This means that the heat accumulated in the water can persist for weeks, even after air temperatures have fallen. The warming of the sea is also cause for concern because of its potential effects on marine ecosystems. Persistently high temperatures can favour the onset of marine heatwaves, alter the distribution of species, increase stress on certain habitats and affect economic activities linked to the sea, such as fishing. Puertos del Estado manages one of Europe’s main oceanographic observation networks, made up of 15 deep-water buoys, 14 coastal buoys, 46 tide gauges and a network of high-frequency radars that allow real-time monitoring of variables such as water temperature, wave height, sea level and ocean currents. The World Meteorological Organization has recently warned of a high probability that global thermal anomalies will continue over the coming months, while various scientific bodies caution that the Mediterranean is among the regions most vulnerable to climate warming.