Heat levels “exceptional” for the month of November were recorded on the night of Sunday 24 to Monday 25 November 2024 as well as in the morning, with for example more than 26 °C in Pau, and 25 °C recorded at 7 a.m. by Météo Pyrénées according to 20 Minutes . The cause is global warming and a Foehn effect, according to Météo France.
The night was “extremely mild across the whole country, and even more so in the South-West”, explains to theAFP Matthieu Sorel, climatologist at the meteorological institute. “Simply crazy!” “, comments a user on X.
According to the climatologist, the phenomenon is explained by the presence of a “South wind everywhere”, which brings “great sweetness”, “accentuated by the Foehn effect” in the Pyrénées-Atlantiques, Landes and Hautes-Pyrénées, under the influence of the Pyrenean relief.
Foehn effect
The Foehn effect, which can occur at any time of the year, occurs when the wind crosses a mountain barrier, and experiences a “significant warming of the air mass”. “This is what we observed last night, where the temperature reached 26.3°C in the middle of the night in Pau,” underlines Matthieu Sorel.
Also recorded were 23.6°C in Biarritz, 23.4°C in Tarbes, and 24.4°C in Orthez, temperatures “extremely soft” at this time of year. The Foehn effect was also observed in Brittany during the weekend.
“It was 3°C warmer on the north coast […] only on the south coast, because this air mass was raised by the Armorican relief and then descended towards the Emerald Coast”, where “nocturnal mildness records” were beaten locally for the period, with for example 15.6°C on the island of Bréhat.
Climate change marker
Late Monday morning, the wind was picking up. “to tip and the foehn effect to stop”, continues the climatologist with theAFPso that the temperature “is going downhill”, with for example 14°C in Biarritz.
The temperatures observed last night reached “very very high levels, very impressive” for the month of November, explains the climatologist.
“Air masses like that, for this time of year, are something we don’t see, without climate change,” he explains, “we have temperatures well above normal everywhere”, 15°C in Lille, 16°C in Paris, 17°C in Besançon.
Globally, “we have small cold anomalies” as illustrated by the recent early winter episode, with significant snowfall in the northern half of France last Thursday, and “very large warm anomalies”, “it is indeed a marker of the climate change in which we are experiencing”, says Matthieu Sorel.
