Water temperature in Spain

Spain's Mediterranean and Atlantic shores

Spain has two very different coastlines. The Mediterranean, from Catalonia to Andalusia and around the Balearic Islands, warms steadily through early summer and is at its warmest in August and September. The north coast along the Cantabrian Sea and the Bay of Biscay is cooler and wilder. On Andalusia's Atlantic side near the Strait of Gibraltar, wind can bring cold deep water to the surface, so the sea may feel chilly even in a heatwave. Inland, the rivers of the Ebro basin are the main focus.

Much of the data for the 327 sites is modelled. Most coastal temperatures come from the Open-Meteo marine model and are marked as model values in the app. Measured readings come from buoys and coastal stations distributed by the Copernicus Marine Service, with SOCIB adding stations around the Balearics. On the Ebro and tributaries such as the Arga, Ega and Gállego, the SAICA network of the Ebro basin authority provides measurements. The beaches themselves are tested by the authorities independently of these temperature sources.

Regional authorities sample beach water during the season, and ratings follow the EU Bathing Water Directive from excellent to poor. Lifeguarded beaches use green, yellow and red flags to show whether swimming is advisable. On the north coast and the Atlantic, surf and rip currents deserve respect, while jellyfish appear from time to time in the Mediterranean in summer. Around the Strait of Gibraltar, the Levante and Poniente winds can change conditions within a single day.