Weather Natural phenomenon cooled Lake Geneva by eight degrees over Whitsun
Over the Whitsun weekend, the water temperature in Lake Geneva dropped from 19 to 11 degrees in just a few days. According to experts, the reason for this abrupt drop in temperature is a phenomenon that has already caused even greater drops in temperature.
10.06.2025, 12:05
SDA
A strong south-westerly wind displaced the warm surface water in the Lake Geneva basin to the north-east. To compensate for this, cold water rose from the depths, explained the Swiss Federal Institute of Aquatic Science and Technology (Eawag) in a statement on Tuesday. This process is known as upwelling.
The phenomenon occurs in Lake Geneva almost every year in early summer. The sharpest known drop in temperature to date was observed at the end of June 2017. At that time, the water temperature at the Bains des Pâquis lido in Geneva dropped from 23 to just 8 degrees in the space of two days.
