Germany’s North Sea hits record temperatures in summer 2025
Clean Energy Wire
Water temperatures across large areas of Germany’s North Sea were two degrees higher than the long-term average, the Federal Maritime and Hydrographic Agency (BSH) said. Water temperatures in June, July, and August reached an average of 15.7°C, the warmest summer since records began in 1969, according to preliminary data by BSH.
The agency examines the surface temperatures of the North Sea and Baltic Sea on a weekly basis, combining satellite data with measurements from stations and ships. It calculates the long-term average by taking weekly averages for summer months from 1997 to 2021.
Marine heatwaves are becoming longer and increasing in frequency, BSH said. Temperature variations differed locally, with temperatures two to three degrees above the long-term average across large areas of the western and southwestern North Sea up to the English Channel, BSH said. In the east and southeast, water temperatures were up to 1.3 degrees warmer than usual.
“We see a connection with a pronounced marine heatwave off Norway this summer, which had an impact on the North Sea – a phenomenon that is occurring more frequently in times of climate change,” said Dagmar Kieke, who led the survey expedition on the research vessel ATAIR.
The year 2025 has been marked by higher water temperatures in the North Sea, with records reached at the start of the year as well as in spring. Warming oceans come with far-reaching consequences for the marine environment, which in turn influences weather and climate patterns.
