Water temperature in the Netherlands

Dutch coast, rivers and lakes

The Netherlands swims in the North Sea, in large inland waters and in many small lakes. The shallow North Sea off the Hollandse Kust warms slowly and usually peaks in August or early September. Shallow inland waters such as the IJsselmeer and Markermeer warm up faster in early summer. The Rhine enters the country at Lobith and splits into many branches on its way to the Haringvliet, and flowing rivers stay a little cooler than still water.

Rijkswaterstaat supplies the majority of the 149 sites, measuring continuously on rivers, canals, harbours and offshore, from Lobith and Amsterdam to IJmuiden and Den Oever. Additional measured North Sea values come from platforms and buoys distributed by the Copernicus Marine Service. Only a few places use the Open-Meteo marine model, and those values carry a model label. Smaller swimming lakes are hardly represented in this dataset so far.

The provinces test official bathing sites during the season and rate them from excellent to poor under the EU Bathing Water Directive. Blue-green algae can appear in lakes during warm spells, prompting warnings. Along the North Sea coast, rip currents form near groynes and breakwaters and can carry even strong swimmers away. Swimming in the major rivers is dangerous because of commercial shipping and strong current, and Rijkswaterstaat advises against it.