France is set to see another week of high temperatures, which could break May records in several regions, new weather forecasts suggest.
National weather service Météo France has stated that temperatures, which have dipped very slightly over the last couple of days, “will start rising again, culminating in very high temperatures in the middle of the week, between Wednesday and Thursday, or even Friday.
“Maximum temperatures will be between 30°C and 34°C in the majority of regions, excluding those close to the English Channel and the Mediterranean coastline.”
️ La #chaleur qui s'est installée depuis le début du mois se poursuit cette semaine. Le mercure va repartir à la hausse, pour atteindre, en milieu de semaine, 30 à 34°C sur la plupart des régions.— Météo-France (@meteofrance) May 16, 2022
Aix-en-Provence via @infoclimat pic.twitter.com/OovXI5sEjX
Some cities, including Lyon, could see at least five consecutive days with highs exceeding 30°C, which is “an extremely rare event in May,” Météo France added.
Caused by a heat dome
The hot temperatures predicted in weather forecasts are the result of a ‘heat dome’, which occurs when an anticyclone slows over a certain area of land, holding a mass of hot air in place.
High pressure from the atmosphere pushes the air down, compressing it and shrinking the volume of its net heat. This causes it to grow even hotter, but as it attempts to rise it is pushed down once again by the high pressure, which acts like a dome, trapping the heat inside.
Un dôme de #chaleur se met en place toute la semaine sur la France, bien visible avec cette animation de la masse d'air. La vague de chaleur va durer jusqu'à vendredi et s'annonce exceptionnelle pour un mois de mai. pic.twitter.com/lfMAbh29zg— La Chaîne Météo (@lachainemeteo) May 16, 2022
Generally, heat domes only last for seven to 10 days, but are becoming more common as a result of climate change.
Météo France climatologist Matthieu Sorel told Ouest France: “This is a hot spell which is sustained, widespread and intense, exceptional for this time of year.”
However, it cannot yet be classed as a heat wave, because the average temperature recorded across 30 different locations in France has not exceeded 25.3°C for three days in a row.
From Friday (May 20), temperatures will begin to fall, returning to normal by May 24.
However, Mr Sorel added that this hot episode “should make May 2022 the hottest ever recorded” in France, beating May 2011 to the title.
The record for the highest number of consecutive days where temperatures were above average could also be broken this week. Yesterday (May 16) was the 36th day of hotter than normal weather, drawing close to 2007’s record 38 days.
“The heat will unfortunately worsen the dryness” of French soils, Mr Sorel warned. “In the context of climate change, heat wave periods become more frequent, and tend to set in earlier in the spring than before.”
However, a hot May does not necessarily mean that the following summer will also be especially hot.
Forest fire near Rennes
The dryness of the earth, paired with the heat, contributed to the spread of a forest fire near Rennes (Ille-et-Vilaine) yesterday.
Some 25 hectares of land were burnt in the Forêt de Rennes, requiring the mobilisation of 125 firefighters and 35 vehicles.
The fire began around midday on the edge of the A84 road heading towards Caen, although its source is unknown. The wind helped it to move rapidly towards the northeasterly corner of the forest, and the blaze disrupted traffic heading in both directions on the A84.
At 18:00 the fire service announced that the fire had been brought under control.