Initial estimates indicate 1,260 heat-related deaths in Switzerland in summer 2026

Analyses by Swiss TPH researchers show that the hot summer of 2026 had a considerable impact on mortality in Switzerland. For the period from May to August 2026, the number of heat-related deaths is provisionally estimated at 1,257, which represents 5.5% of all deaths between beginning of May and end of August 2026. Around 85% of these deaths occurred among people aged 75 and over. Around 70% of heat-related deaths are attributed to hot or very hot days, defined as days with a daily mean temperature of 25°C or more (hot) or 27°C or more (very hot). The estimated number of heat-related deaths in the summer of 2026 is similar to that of the summer of 2003, noting that September 2026 is not included yet. These results confirm once again that heat is the natural hazard responsible for the highest number of deaths in Switzerland.

“These provisional results show that heat continues to cause many deaths, especially on the hottest days.”, said Martina Ragettli, Head of Climate, Health and Policy at Swiss TPH. “There are signs of adaptation to moderate heat, but less so for extreme heat. Older people remain most affected, but younger people are also at risk. As more hot summers are expected, public health measures will need to be further strengthened.”

Each year, Swiss TPH estimates the number of heat-related deaths in Switzerland on behalf of the Federal Office for the Environment (FOEN) and the Federal Office of Public Health (FOPH) (Hitzebedingte Sterblichkeit). These initial estimates for 2026 were produced on behalf of the FOPH, based on daily mean temperatures and provisional daily mortality data, and do not yet include September. Final figures, along with more detailed analyses, will be published in spring 2027.
 

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