The swim map

• Green: Excellent or Good quality. The water has passed its samples year after year.
• Orange: Satisfactory. Approved, but with a thinner margin.
• Red: Poor quality. Samples have shown too much bacteria several seasons in a row.
• Grey: no classification yet, usually a new site or too few samples.

The classification follows the EU bathing water directive and is based on four seasons of bacteria samples, so one bad day does not change a site's colour. The latest sample in each pin tells you about right now.

Fit for bathing means the latest sample found low levels of the bacteria E. coli and intestinal enterococci, so the water is considered safe to swim in. Fit with remarks means slightly elevated levels, swimming is fine but the municipality follows up. Unfit for bathing means the levels were too high, and bathing is advised against until new samples come back clean.

The municipalities sample the EU bathing sites several times through the season, roughly June to August. The map shows the latest sample for every site, with the water temperature where it was measured, and takes its data from the Swedish Agency for Marine and Water Management's Badplatsen register.

An algal bloom means cyanobacteria have multiplied rapidly, often visible as a green or blue-green film on the water. Some blooms produce toxins that can cause skin irritation and stomach trouble, so avoid swimming during a bloom and keep an extra eye on children and dogs. Sites with a reported bloom carry a warning on the map.