Switzerland records its hottest summer on record

Switzerland’s national summer average reached 17.2°C, the highest recorded since measurements began in 1864. MeteoSwiss said the June to August figure exceeded the previous record, set in 2003, by 0.4°C. It stood 3.4°C above the 1991 to 2020 average, placing the 2026 summer well outside recent climate conditions.

The heat spread across the country, with the strongest departure in northwestern Switzerland. Temperatures there averaged 4°C above the long-term norm, according to MeteoSwiss. Basel-Binningen reached 39.7°C on July 30, matching the highest temperature recorded north of the Alps at Geneva-Cointrin on July 7, 2015.

The figures matter beyond weather statistics. Farmers entered the summer facing heat and drought that can reduce yields, increase irrigation needs and damage crops at critical stages of growth. Switzerland’s fragmented agricultural landscape gives producers limited room to absorb repeated losses or invest in expensive infrastructure.

MeteoSwiss also recorded new local records at 30 weather stations. Almost half of those records came in June, indicating that the season began with exceptional heat rather than building gradually toward a single late-summer peak.

Thirty weather stations set new heat records during the summer, while tropical nights reached a national total of 50. MeteoSwiss defines a tropical night as one in which the temperature does not fall below 20°C. Switzerland recorded eight more tropical nights than in 2003, the previous record summer.

The difference was especially visible in places such as Neuchâtel and Glarus. Both locations recorded 18 additional very hot days compared with the earlier record. Persistent night-time heat gives people, animals and crops less opportunity to recover after daytime temperatures climb.

The country’s highest readings were not confined to lowland cities. On June 27, the thermometer in Scuol, Graubünden, reached 35.1°C at an altitude of 1,304 metres. That reading illustrates how heat is reaching elevations usually associated with cooler conditions.

Basel-Binningen’s 39.7°C peak tied the north of the Alps record, but the wider pattern carries more significance than any single measurement. Repeated hot days, warm nights and unusually high temperatures across different elevations create pressure on water supplies, public health systems, livestock management and mountain ecosystems. MeteoSwiss’s station data show a summer defined by breadth as well as intensity.

Swiss fruit growers are already seeing the cost of hotter, drier summers in smaller harvests. Achim Walter, a professor of crop science at ETH Zurich, told Swissinfo that traditional varieties were planted for older temperature and rainfall patterns. Drought can make fruit sweeter under intense sunshine, but it can also leave the fruit smaller and cut total yields.

That pressure is pushing growers to reconsider which varieties belong in Swiss orchards. Heat-resistant apples, including Pink Lady, are becoming more important. Olive trees are already being cultivated at farms north of the Alps, and Walter expects southern European crops to move farther north as conditions change in their traditional producing regions.

Pawpaw, sometimes called the northern banana, could also attract interest. Walter said it tolerates winter temperatures as low as -30°C and performs well in summer heat. Almonds may suit a warmer climate, although Switzerland’s damp periods can encourage fungal disease.

Crop changes will require more than warmer weather. Swiss farms are often small and fragmented, and new varieties involve planting costs, technical expertise and uncertain markets. Plant protection products may also need authorisation for crops that have not previously been widely grown in Switzerland.