Summer has only officially started a few days ago, but Haute-Savoie is already experiencing its first major heat wave of the year. Météo-France has placed the department under orange heatwave alert starting Thursday, June 18 at noon. Temperatures could locally reach 34 to 36°C in the plains, while the heat will also spread to the mountain valleys.
After several already very hot days, the weather situation is reaching a new level. Forecasters are talking about a prolonged episode, characterized by exceptionally high temperatures for the season and particularly mild nights that will prevent the body from properly recovering.
Up to 36°C in the hottest valleys
According to the forecasts, maximum temperatures should reach between 34 and 36°C in several areas of Haute-Savoie.
The valleys of the Arve, the Genevois and the urban areas around Annecy and Annemasse are among the most exposed territories. Even at altitude, the heat will be unusual: 30°C could be reached up to around 1,000 meters of altitude.
Even more worrying, nighttime temperatures will remain high. In some municipalities, the mercury may not drop below 20°C, especially in urban centers where heat islands increase the feeling of discomfort.
The mountains offer some respite, but not everywhere
Facing this heat wave, many residents and tourists are expected to seek coolness at altitude.
Areas located above 1,500 meters will maintain much more pleasant temperatures. The alpine pastures of the Aravis massif, the heights of the Grand Massif and some hikes in the Chablais could thus become favored destinations in the coming days.
However, be careful: even in the mountains, sun exposure remains intense. Professionals recommend leaving very early in the morning, limiting exertion during the hottest hours, and carrying sufficient water reserves.
Risks for vulnerable people
As with every heat wave episode, the authorities call for vigilance, especially concerning:
- elderly people;
- young children;
- people suffering from chronic illnesses;
- outdoor workers;
- athletes and hikers.
Early signs of heat stroke may include headaches, unusual fatigue, dizziness, nausea, or elevated body temperature.
Possible storms by the end of the week
This heat wave could however evolve over the next few days.
The arrival of more humid air over the Alps could favor the development of storms in the late afternoon, especially over the reliefs. These phenomena could locally bring some freshness, even if temperatures are expected to remain well above seasonal normals.
Good habits to adopt
Facing this orange alert, the recommendations remain the same:
- drink regularly without waiting to feel thirsty;
- avoid physical activities during the hottest hours;
- prefer cool or shaded places;
- close shutters and windows during the day;
- regularly check on isolated people.
With this first real heat wave of the year, Haute-Savoie is about to experience several particularly trying days. For those who can, lakes, waterfalls and high-altitude hiking trails could become the most sought-after refuges in the department.
