Water quality in Oulu’s winter swimming places is good November 10–11, 2025

18.11.2025

The Environment Office of the Oulu Region has taken water samples from all official winter swimming places in its operational region on November 10–11. 2025. The water quality at all winter swimming places met all quality criteria based on indicator bacteria. The results can be viewed on Table 1 (in Finnish). The current water quality samples were the first for the winter season 2025–2026. The next samples from winter swimming places will be taken in February of 2026.  

Table 1: Water sample study results of public winter swimming places in the Environment Office of the Oulu Region’s operational region Nov 10–11, 2025 (in Finnish)
pdf 82.49 KB

Water quality is assessed based on levels of so-called indicator bacteria (E. Coli and intestinal enterococcus). Indicator bacteria indicate the amount of intestinal contamination of swimming water. The indicator bacteria do not necessarily cause stomach diseases or other symptoms but if the bacteria levels are high, the swimming water could contain bacteria or viruses that cause diseases. Different indicator bacteria are utilized for assessing inland waters and coastal waters (salt waters). The action levels of indicator bacteria are listed in Table 2 (Ministry of Social Affairs and Health’s decrees 354/2008 and 177/2008). 

Table 2: Action levels of singular swimming water samples, also utilized for winter swimming places (in Finnish).
pdf 50.66 KB

Further information from the Environment Office of the Oulu Region 
Environmental Health advice phone on weekdays 9.00–15.00, tel. 044 703 6700 

The newest swimming water samples can be read here ouka.fi/uimarantojenvesi (in Finnish). 

sport and exercise
outdoors and nature
environment