Baltic Sea experiences record warm temperatures near Helsinki amid climate concerns

The Baltic Sea has experienced exceptionally warm waters throughout this autumn, particularly near Helsinki, where temperatures at a measuring point in the Gulf of Finland have reached approximately 18 degrees Celsius. Typically, this period sees water temperatures around 13 degrees. According to doctoral researcher Veera Haapaniemi from the Finnish Meteorological Institute, a marine heatwave has persisted despite cooler weather, with temperatures several degrees above the averages recorded from 1991 to 2020.

This heatwave is defined by a surface water temperature remaining within the top ten percent of historical temperatures for at least five consecutive days. Impressively, the ongoing heatwave has lasted a record 50 days. Coastal observation stations have noted the phenomenon for about 20 days, effectively covering the entire month of September. The heatwave at the buoy has been ongoing since early August.

The rising global surface temperatures are also evident in the Baltic Sea. Climate change is expected to prolong and intensify marine heatwaves. Haapaniemi highlights that increasing occurrences of such extreme weather patterns signify notable climate changes.

The Finnish Meteorological Institute is monitoring near-real-time temperatures of the coastal waters. Such observations can help indicate whether an unusually warm period is ongoing. While surface temperatures may soon drop quickly if winds intensify, understanding how heat progresses below the surface is crucial for assessing impacts on marine ecosystems.

Concerns have grown among researchers regarding rapid warming, with significant increases in global ocean temperatures noted in recent years. As environmental expert Markku Viitasalo points out, this could lead to more severe storms and changes in marine biodiversity, with potential consequences for fishing and food security in various regions.