Authorities raise heatwave danger level in southern Switzerland

The level‑4 heatwave warning has now expanded to large parts of Switzerland. Keystone-SDA

The heatwave danger level was raised from 3 to 4 across much of canton Ticino on Wednesday. On Tuesday, the high-risk zone (level 4) already extended across the central Swiss Plateau region and French-speaking Switzerland.

The level‑4 heatwave warning has now expanded to large parts of Switzerland. It covers areas north of the Swiss Plateau up to the Rhine Valley in cantons Graubünden and St Gallen, the Lake Geneva region as far as Orbe, central Valais, the Three Lakes region, and the area from Basel to the northern reaches of the Delémont district.

By 11 am on Wednesday, temperatures had already reached 31.1°C in Wynau, canton Bern – the highest temperature recorded at that time – and 30.0°C in Basel‑Binningen. In French‑speaking Switzerland, Neuchâtel was the hottest location at 29.9°C, followed by Pully, canton Vaud, at 29.2°C and Delémont at 28.7°C.

According to MeteoSwiss, level 4 corresponds to a “high risk” heatwave. This means daytime temperatures exceed 27°C for at least three consecutive days, with little or no cooling at night. Such conditions significantly increase the risk of circulatory problems and general physical discomfort.

The ongoing heat is also unlikely to ease the already elevated fire risk. Much of Switzerland remains at level 3 (considerable danger). Only the Vaud Alps, the Upper Engadine, canton Graubünden, and the cantons of Schwyz and Schaffhausen are at level 2. By contrast, parts of Valais, northern Graubünden, and Liechtenstein are facing a high (level 4) or even very high (level 5) risk.

Translated from French, sub-edited by sb