Gulf of Bothnia Water Temperature Today & Regional Overview
We find every place where you can swim and show you the water temperature there today and throughout the year.
Current Water Temperature
The water temperature in the Gulf of Bothnia today ranges from 8.5°C (Ursviken, Sweden) to 15°C (Naantali, Finland).
As of today, the minimum water temperature in the Gulf of Bothnia ranges from 47°F (8°C) to 50°F (10°C). This is still cool water, suitable only for experienced swimmers or those accustomed to cold water. Swimming in such conditions is possible, but not recommended for prolonged periods. Extra caution should be taken during extended exposure, as the cold water can cause heat loss and lead to hypothermia. For added comfort, special clothing can be used.
It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Sea Temperature Trends
Over the past month, the water temperature in the Gulf of Bothnia has increased by 7°C. In general, the sea water temperature remains within the statistical range for this time of year.
Water Temperature and Swimming Conditions Throughout the Year
| Month | Min | Max |
|---|---|---|
| January | -2°C | 5°C |
| February | -1°C | 4°C |
| March | -2°C | 3°C |
| April | -2°C | 5°C |
| May | -2°C | 13°C |
| June | 1°C | 19°C |
| July | 9°C | 24°C |
| August | 11°C | 24°C |
| September | 6°C | 20°C |
| October | 0°C | 16°C |
| November | 0°C | 11°C |
| December | -2°C | 7°C |
The Gulf of Bothnia, the northernmost arm of the Baltic Sea between Finland and Sweden, has characteristically cool, brackish waters that vary substantially with the seasons. Winter surface temperatures typically hover around the freezing point, often ranging from about -0.5°C to 3°C depending on local salinity and ice cover, and large areas freeze over from late autumn to spring. In spring the water warms gradually, commonly between 0°C and 10°C as ice breaks up. Summer brings the warmest conditions: surface temperatures in the southern Bothnian Sea commonly reach about 16°C to 20°C in warm years, while the northern Bothnian Bay tends to stay cooler, roughly 10°C to 16°C. During autumn temperatures fall back toward roughly 5°C to 15°C before the onset of winter ice.
Swimming Conditions
Swimming in the Gulf of Bothnia is permitted and widely practiced during the ice-free season, especially at beaches and sheltered bays where surface temperatures are most comfortable. The brackish, shallow nature of many areas means sheltered spots warm faster and can be pleasant in summer, but open stretches remain relatively cool. Ice and near-freezing conditions make unsupervised winter swimming hazardous because of the risk of hypothermia and unstable ice; nevertheless, winter and ice-swimming are traditional in the region and are undertaken by experienced people with appropriate safety measures, such as saunas, ice holes, and support on shore. As with any cold-water environment, swimmers should assess local conditions, heed warnings, and use caution when temperatures are low.