Swiss Rivers and Lakes Remain Critically Low Despite Rain.

Switzerland continues to experience drought conditions as water levels in many rivers and lakes remain significantly below normal despite recent rainfall. According to measurements from the Federal Office for the Environment (FOEN), several major waterways across the country are still showing unusually low levels for this time of year.

The High Rhine, Reuss, and Limmat rivers remain below their seasonal averages, highlighting the ongoing impact of dry weather conditions that have persisted for months. While this week’s rain provided temporary relief, experts say it has not been enough to restore water levels to normal.

Lake Constance and Lake Zug are among the most affected areas. Hydrologists attribute the situation to prolonged drought combined with above-average temperatures, which have increased evaporation rates across Switzerland. The combination of reduced rainfall and warmer weather has placed additional pressure on lakes, rivers, and surrounding ecosystems.

Earlier this month, the western section of Lake Constance reached a historic low water level, creating challenges for navigation and transport. Since the end of April, a stretch of the Rhine River between Stein am Rhein and Diessenhofen has remained impassable due to insufficient water levels. However, shipping operations on Lake Zug and Lake Aegeri have continued without major disruptions despite the challenging conditions.

Environmental experts warn that extreme fluctuations between high and low water levels are becoming increasingly common. Unregulated bodies of water such as Lake Constance and Lake Walen are particularly vulnerable to changing weather patterns. According to Swiss Shipping Company Untersee und Rhein, these fluctuations have intensified in recent years, making water management and navigation more difficult.

The contrast has been striking. In June 2024, authorities issued the highest-level flood warning for the Untersee region. Less than a year later, the same area recorded historically low water levels. Experts say this demonstrates the growing unpredictability of weather patterns and the challenges they create for communities, businesses, and transport networks.

As Switzerland faces another dry season, authorities and industry leaders are exploring long-term solutions to maintain navigation, protect water resources, and adapt to increasingly extreme weather conditions. The situation continues to be closely monitored as concerns grow about the environmental and economic impacts of prolonged drought.

Swiss Lakes Hit Record High Temperatures in May.

Switzerland’s lakes are experiencing unprecedented warmth, with many recording their highest-ever temperatures for the month of May. According to recent reports, 26 of the country’s 32 largest lakes have reached record surface temperatures, highlighting the growing impact of warmer weather and climate change.

Several well-known lakes, including Lake Zurich, Lake Geneva, Lake Maggiore, Lake Lucerne, and Lake Brienz, have all recorded unusually high temperatures. On Saturday, many lakes exceeded 20°C, a level typically associated with warmer summer periods rather than late spring.

Lake Murten recorded the highest temperature at 24.6°C, followed by Lake Geneva at 23.6°C. Lake Zurich reached 22.4°C, while Lake Maggiore measured 21.8°C. Lake Lucerne and Lake Biel also exceeded seasonal averages, both recording temperatures of 20.3°C.

Scientists warn that warmer lake water can create environmental and health challenges. Higher temperatures encourage the growth of blue-green algae, bacteria, and cercaria, commonly known as duck fleas. These microscopic larvae can trigger allergic skin reactions and severe itching in swimmers.

Researchers from the Swiss Federal Institute of Aquatic Science and Technology (Eawag) believe that duck fleas could become more widespread in Swiss lakes during future summers as water temperatures continue to rise.

The warming trend also threatens aquatic wildlife. Cold-water fish species such as trout and char require oxygen-rich environments to survive. Experts explain that prolonged water temperatures above 20°C can become dangerous for these species, affecting their growth, health, and survival rates.

Climate specialists warn that rising lake temperatures are placing increasing pressure on freshwater ecosystems across Switzerland. As extreme weather patterns become more frequent, scientists are closely monitoring lake conditions and their impact on biodiversity.

The record-breaking temperatures serve as another reminder of the environmental challenges linked to a warming climate and the need for continued conservation efforts to protect Switzerland’s natural resources.