Swiss heatwave linked to about 1,260 deaths

An estimated 1,257 people died from heat-related causes in Switzerland between May and August 2026, according to a provisional analysis reported by SRF. About 85 percent of those who died were aged 75 or older.

The estimate equals 14 deaths per 100,000 residents and 5.5 percent of all deaths during the period. It comes from the Swiss Tropical and Public Health Institute, which carried out the analysis for the Federal Office of Public Health. Tamedia newspapers first reported the figures.

Seven in ten of the estimated deaths were attributed to days with an average temperature of at least 25 degrees Celsius. Of these, 485 occurred on hot days with average temperatures from 25 to 27 degrees, and 400 on very hot days with averages of at least 27 degrees.

The estimate is in a similar range to the number of deaths during the 2003 heatwave. A direct comparison is not yet possible because the 2026 analysis covers only May to August, while historical figures run through the end of September.

The estimate is based on daily average temperatures measured by MeteoSwiss and preliminary death records from the Federal Statistical Office. Final figures are expected in spring 2027 and will include September, with further breakdowns by age, sex, major region and canton.

In September, the Federal Council said it expected excess mortality due to heat, citing about 570 additional deaths among people over 65.