About
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You can support the site in several ways: follow me on social media, leave a 5-star review on Google, share with your friends, or put up new QR posters in your area. All the details are available in the menu.
The project
lake.lindt.one provides real-time temperatures of Swiss and French lakes. Data is updated in real time and interpolated to offer a continuous estimate.
The story
The site was created in 2020 by Nicolas Lindt, from the canton of Vaud and a keen cold water swimmer in Lake Geneva. Initially built for a single beach (Lutry), the project quickly expanded to over 50 beaches along the Swiss and French shores of Lake Geneva, then to Lakes Joux, Morat, and other lakes in western Switzerland. QR posters, which anyone can print and put up in their area, allow swimmers to check the water temperature right from the beach. Adhesive stickers with a QR code are also available, using the swimmer's geolocation to display the nearest beach.
How does it work?
The displayed temperatures come from Alplakes 3D hydrodynamic simulations, which model the thermal state of lakes using meteorological data. For some lakes such as Lake Geneva, an IDW (Inverse Distance Weighting) calibration layer has been added: this method weights the differences between the model and actual measurements from nearby stations, giving more weight to the closest stations, in order to improve local accuracy and the model's responsiveness to rapid temperature changes.
Data sources
Temperatures come from Alplakes, a platform developed by Eawag (Swiss Federal Institute of Aquatic Science and Technology). Alplakes uses 3D hydrodynamic models (Delft3D-Flow, MITgcm) combined with meteorological data to simulate the thermal state of over 100 Alpine lakes. Temperature predictions are calculated at various depths and updated regularly.