Switzerland feels cost of record summer heat

Since spring, Switzerland has been gripped by an exceptional drought. Between April 1 and July 31, around one-fifth of Switzerland’s monitoring stations recorded their lowest water levels for this period since measurements began. Thomas Hodel / Keystone

Record temperatures and historic drought made April to July the hottest and driest period ever recorded in Switzerland. Here’s how the unprecedented summer heatwave has affected elderly residents, farmers, businesses and nature.

1. Agricultural sector faces heavy losses

Swiss agriculture is facing climate-related losses estimated by the Swiss Farmers’ Association at CHF522 million ($645 million), exceeding the damage caused by the 2003 heatwave. The government has responded with a CHF70 million support package for farmers and forests.

A severe fodder shortage has emerged after Alpine pastures dried out, forcing farmers to bring livestock down from mountain grazing areas early and use winter hay reserves. To ease the crisis, authorities have released up to 16,000 tonnes of compulsory feed stocks and suspended customs duties on imported hay and silage. Some farmers have even importedExternal link hay from Canada.

The fodder shortage has also hit livestock production. According to Proviande data cited by the Federal Office for Agriculture, the number of cows slaughtered between June and August rose 45% year-on-year, an increase of 10,275 animals, likely linked to feed shortages.

The drought and successive heatwaves have led to major crop losses and higher production costs for farmers. Many crop yields are expected to be down.

Alongside lower productivity, farmers have had to make extra efforts to irrigate their crops, which has also led to higher production costs. Market prices are expected to rise, in particular milk and potatoes.

2. Fish suffer unprecedented heat stress

Several rivers and streams broke temperature records set during the hot summers of 2003 and 2018. On July 14, the Aare in Bern reached 24.82°C, while low water levels and reduced flows accelerated warming and depleted oxygen levels.

The drought caused dozens, possibly hundreds, of streams to dry up, particularly on the Swiss Plateau and in the Pre-Alps.

David Bittner, head of the Swiss Fisheries Association, says the final toll could reach “millions of dead fish”, with recovery taking years. Keystone / Anthony Anex

Major Swiss lakes also recordedExternal link their warmest average summer surface temperatures since records began in 1981.

The consequences for aquatic life have been severe. David Bittner, head of the Swiss Fisheries Association, saysExternal link the final toll could reach “millions of dead fish”, with recovery taking years. Cold-water species such as trout, grayling and burbot were especially vulnerable.

Authorities intervened in some regions to prevent mass losses. In canton Bern, over 100,000 fish were manually relocatedExternal link from threatened waterways. Temporary fishing bans were introduced in several areas.

3. Human health: pressure on the health system

Between mid-July and mid-August, the EuroMomo monitoring platformExternal link estimates Europe recorded more than 32,000 excess deaths.

Switzerland has yet to produce consolidated figures for this summer, but the blistering back-to-back heatwaves are thought to have claimed the lives of numerous elderly people.

According to weekly figures published by the Federal Statistical Office, the mortality rate for over-65-year-olds was higher than projected for several weeks in summer. A total of 1,281 people aged over 65 died during the last week of June, for example. The statistics had forecast 1,104 deaths, 177 fewer.

The Swiss Tropical and Public Health Institute (Swiss TPH) estimates around 500 heat-related deaths occur each summer in Switzerland in recent years. During the summer of 2003, Swiss TPH recorded around 1,400 additional deaths. In 2015, it was 747.

A 20 Minutes/Tamedia surveyExternal link found that the extreme summer heat took a heavy toll on Swiss residents, with 74% describing it as “rather” or “very” difficult. Women were disproportionately affected, with 46% reporting the heat as very difficult to cope with, compared with 31% of men. Over a third of respondents reported major physical effects, including sleep disturbances and circulatory problems, with women again reporting higher rates than men (46% versus 29%).

Lausanne University Hospital (CHUV) reported a 10-15% increase in emergency activity this summer, a spokesperson told Swissinfo.

4. As the Rhine drops, fuel costs soar

Low water levels on the River Rhine this summer disrupted a key transport route for Swiss imports, driving up logistics costs and fuel prices.

Switzerland imports fuel, chemicals, consumer and industrial goods, grain/feed products, metals, and construction materials via the Rhine. In 2024, Swiss Rhine Ports handledExternal link 5.4 million tonnes of goods, or 8% of Swiss imports and exports.

This summer, freight tariffs for Rhine barges jumped almost tenfold from around CHF25 to CHF240 per tonne, as vessels were forced to reduce loads in shallow waters.

According to the non-profit Touring Club Switzerland (TCS), transport costs alone added roughly CHF0.16 per litre to fuel prices. Unleaded 98 roseExternal link to CHF2.13 per litre while diesel reached CHF2.27 in late August.

5. Energy: more cooling, less water… but more solar

Record temperatures created headaches for energy officials: increased electricity demand for cooling, while reducing nuclear and hydro production capacity.

Air conditioning and fan sales surgedExternal link. Meanwhile, the drought has had a major impact on electricity production. Water levels in Swiss hydropower reservoirs dropped to their lowest in 20 years, according to the Swiss Federal Office of Energy. Small rivers were reduced to mere trickles. River flows on major waterways, including the Aare, Rhine and Rhône, fell to record lows, reducing electricity output. Hydropower supplies just over half of Switzerland’s electricity.

Warm rivers and low water levels forced nuclear power plants to reduce output across Europe. Switzerland has three active nuclear power plants with four operating reactors, which generate about a quarter to a third of Switzerland’s electricity. Warm river water also forced temporary output reductions at the Beznau nuclear power plant. Both reactors returnedExternal link to full operation only in late August after months of restrictions and shutdowns.

Despite these pressures, Switzerland avoided energy supply shortages partly thanks to the abundant sunshine and strong growth in solar energy.

“Solar energy currently acts as a significant buffer against the unfavourable hydrological conditions in Switzerland,” the Federal Electricity Commission Elcom told Swiss public broadcaster SRF.

Edited by Reto Gysi von Wartburg/ts