Heatwave: 16 departments placed on orange alert from Friday midday

Météo-France has issued an orange heatwave alert starting Friday midday in 16 departments, mostly in western France, which is already experiencing a heatwave that is expected to increase further, according to the bulletin published Thursday at 4 p.m.

The public institution predicts an "early heatwave from Brittany to Charentes via the Centre-Val-de-Loire this Friday" and an "early heatwave in the Rhône and Isère from Friday" . In the western departments, "the hottest day is expected this Saturday, June 20" , warns Météo-France.

The phenomenon, linked, according to the weather forecasting agency, to "anticyclonic conditions over France" , affects the Channel, Morbihan, Ille-et-Vilaine, Mayenne, Sarthe, Loire-Atlantique, Maine-et-Loire, Indre-et-Loire, Vendée, Deux-Sèvres, Vienne, Charente-Maritime, Charente, Haute-Vienne, Rhône and Isère.

On Friday morning, "minimum temperatures are already hot, around 17 to 20°C in the departments of Manche, Rhône and Isère, and 19 to 21°C in the other departments on orange alert," Météo-France emphasizes.

"During the day, maximum temperatures generally reach 33 to 36°C or even 37 to 38°C in places. During the night from Friday to Saturday, the minimum temperatures are again high, from 19 to 22°C," adds the forecaster. Météo-France had already placed a large number of departments in the West and Auvergne-Rhône-Alpes on yellow heatwave alert on Thursday.

These alert levels are established not only according to temperatures but also to the particularities of each department (for example, populations are more accustomed to high temperatures in the South) and health criteria.

This heat is caused by the blocking of a high pressure system over France, a situation sometimes referred to as an "omega blockage" because the shape of the air masses on the map resembles the Greek letter in the shape of a horseshoe. An upper-level depression over the Atlantic will bring up warm air masses present over the Iberian Peninsula.