Blue-green algae status and swimming water quality
The quality of swimming water is monitored throughout the swimming season.
See the summer 2025 survey results on swimming water quality (pdf)
Check from the sampling plan 2025 (pdf) when the water will be sampled and at which beaches.
Why can some beaches have swimming restrictions?
If the water temporarily deteriorates at a beach due to heavy rainfall or other reasons, and a temporary swimming restriction is set, information will be provided separately on this website, on the hel.fi/uimarannat website, on the ulkoliikunta.fi website and on the beach's notice board.
Recommendation to avoid swimming at the beaches along the Vantaa River during heavy rainfall in summer 2024
In summer 2024, the City of Helsinki Environmental Services issued a recommendation to avoid swimming at the Pikkukoski, Pakila and Tapaninvainio beaches during heavy rainfall. The water quality at the beaches along the Vantaa River has been found to temporarily deteriorate during heavy rainfall due to surface runoff and stormwater. Rains over the entire catchment area of the Vantaa River affect the water quality of the beaches along the river. The temporary swimming restrictions are intended to protect swimmers from potential health hazards. For more information on the risks posed by the water quality at Pikkukoski beach, please see the Pikkukoski beach profile (PDF) (in Finnish) .
Water quality at Marjaniemi beach improved
Marjaniemi beach has been subject to swimming restrictions in previous years due to poor water quality, but more extensive monitoring carried out during the 2023 and 2024 swimming seasons shows that the water quality has improved, because of which the beach is currently not subject to any permanent/seasonal swimming restrictions.
Studies and remedial actions were carried out with several parties to improve the water quality: A cross connection between the stormwater and wastewater pipes of a property located by the nearby Mustapuro creek, on the eastern side of Ring Road I, was discovered and fixed. In addition to this, a sewer line along the creek was renovated. The stormwater well at the beach has been emptied and cleaned and changes are planned for the Marjaniemi area in terms of stormwater management. The water quality of Marjaniemi beach was intensively studied in the summer of 2024 as a collaborative project with the Department of Food Hygiene and Environmental Health at the University of Helsinki. An online news post on the topic can be found here (in Finnish): Marjaniemen uimarannan vedenlaatu parantunut | Helsingin kaupunki .
However, in urban areas, heavy rainfall may temporarily reduce swimming water quality. For more information on the risks posed by the water quality at Marjaniemi beach, see the Marjaniemi beach profile (PDF) (in Finnish) .
The municipal health protection authority assesses and categorises the quality of the swimming water at each public beach on the basis of the results of monitoring surveys after the end of the swimming season. The categorisation is only carried out for public beaches, i.e. so-called EU beaches, where the estimated number of swimmers during the swimming season is at least 100 per day. Small public beaches are not categorised. For example, of the beaches along the Vantaa River, only Pikkukoski is a so-called EU beach. The quality of its swimming water was categorised as good after the 2024 swimming season. The measures taken in the catchment area of Marjaniemi beach have reduced the risk of water pollution to the extent that the survey results from previous years are no longer taken into account in the water quality categorisation. As a result, after the 2024 swimming season, the water quality at Marjaniemi beach was categorised based only on the results of the 2024 swimming season as satisfactory. You can find the latest categorisations here:
Swimming water categories and profiles | City of Helsinki
If a beach is temporarily polluted due to heavy rainfall or other reasons, information about the situation will be posted separately on this website, on the hel.fi/uimarannat website, on the ulkoliikunta.fi website and on a notice at the beach.
Blue-green algae on beaches
Almost every summer, blue-green algae, which can be poisonous, is found at beaches. The amount of blue-green algae typically increases in July when the water temperatures rise, and the blue-green algae situation can change very quickly.
Signs of blue-green algae include green water and green algae stripes visible on the beach. A small amount of blue-green algae is visible in the water as small stick- and nugget-like formations.
What to do when there is blue-green algae in the water:
- Avoid swimming.
- Do not allow small children or pets into the water. Make sure that children and pets do not drink water that has blue-green algae.
- Do not use water containing blue-green algae as washing water or sauna water.
- If you swim or wade in water containing blue-green algae, immediately rinse your skin with clean water.
Hygiene at the beach
You can get sick at the beach if a person with a stomach disease spreads norovirus, for example. Do not go to the beach if you have symptoms of a cold or stomach disease.
Maintaining good hygiene is important at the beach as well. Wash or disinfect your hands after going to the toilet. Children’s diapers may not be changed and children’s bottoms may not be washed in the swimming water.
Do not swim if you have wounds or if the surface of your skin is otherwise broken. Bacteria enter a swimmer’s body through broken skin and can cause an infection. Swimming is not recommended for people who have a skin infection as the bacteria can spread in the water.
Report harmful water
If you suspect that swimming water has caused illness or harm, you can report the case in the Ilppa service.
Notifications received through Ilppa are not processed on a daily basis. In case of an acute emergency, inform the lifeguard or call the emergency number 112.
Report harmful water in the Ilppa service (in Finnish)(Link leads to external service)
Please note that the Ilppa service is not for reporting algae sightings. Algae sightings can be reported in the Vesi.fi map service.
Report an algae sighting in the Vesi.fi map service (in Finnish)(Link leads to external service)