The swimsuits have barely been put away in the wardrobes, and we already have to get out the sweaters and down jackets. The week is going to be particularly gloomy and cool almost everywhere in France, except near the Mediterranean, indicates Météo-France. Temperatures will drop a little more from Wednesday with the arrival of polar air. How can we explain this freshness? Will it last? France Bleu takes stock.
“Fresher air of maritime polar origin” arrives in France
On Wednesday, rain coming from the Channel will “gradually sink into the country”. These showers will be followed “by cooler air of maritime polar origin” which will spread across the entire territory, indicates Météo-France on its website. Specialists call this phenomenon a polar drop: the descent of an air mass from the polar circle to France which causes exceptionally low temperatures. This drop, clearly visible in the video below, is formed because of “an anticyclone that retracts over the Atlantic and guides the flow from the north” towards the hexagon. But Christelle Robert, forecaster at Météo-France, wants to reassure: polar temperatures are not going to hit the country. “The air mass becomes milder as it moves between the Arctic Circle and France”she told France Bleu.
Temperatures well below average
According to Météo-France, “The maximum temperatures are below seasonal averages, with 17 to 18°C in the northern half, 19 to 22°C in the southwest” from France. This mass of fresh air will reach the “Mediterranean rim and Corsica on Thursday, while temperatures” will drop further “a step ahead of the rest of France.” Snow will even return from 1500 m in the Alps.
Temperatures will be between 5 and 7 degrees below seasonal averages this Wednesday. Météo-France expects 7°C in the morning in Lille (North) and 14°C in the afternoon (-6 degrees compared to normal, but also 6°C minimum and 15°C maximum in Clermont (8 degrees below normal) or between 11 and 18°C in Toulouse (-7 degrees). The night from Thursday to Friday will be particularly cool. “with still a risk of frost (white frost, editor’s note) in places, in the Massif Central or the North-East”notes Météo-France. The sun should reappear from Thursday. The weekend will be sunny with temperatures slowly rising “from Friday”. The rise in temperatures is more pronounced on Saturday and even more marked on Sunday.
Is this freshness in September rare?
According to Météo-France, “episodes of marked coolness in September have already occurred in the recent past” with snow above 2000 m in the Pyrenees and the Alps in September 2020. The coolness had also been noted between September 13 and 19, 2017. If these temperatures contrast with the heat of September 2023, “A cooler sequence in September is not incompatible with the context of climate changethe organization specifies. Year-to-year variability is part of our climate. The dynamics of the atmosphere, and the positioning of action centers (anticyclones and depressions), will drive the currents and the movement of air masses, and can induce cooler periods at any time of the year, but these events are becoming rarer and less intense than before.”
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