New temperature records were broken this weekend in France. After a month of October when the values were durably higher than the seasonal averages, the month of November also shows, for the moment, particularly high levels in several regions.
On Saturday, the so-called mildness threshold, that is to say more than 20°C, was exceeded in several areas in the west and south-west of the country in particular. The calendar, however, displayed the date of November 12, the heart of autumn and even the period of the first winter assaults in certain years.
The meteorologist Guillaume Séchet shows, with map support, which regions have been affected by these values, sometimes worthy of summer. This is the part of France lying west of a line Le Havre (Seine-Maritime) – Grenoble (Isère).
On the side of Météo France, forecaster Gaétan Heymes reports several records broken on Saturday. Never so late in the season had it been so hot in cities like Albi (Tarn), Agen (Lot-et-Garonne), Nantes (Loire-Atlantique), Le Mans (Sarthe) or on the island of Batz , in Finistère.
The map it broadcasts in support of the temperatures recorded shows the deviation from the seasonal averages. It thus made up to ten degrees more than the temperatures normally expected at this time of the year. These levels are reached only for a few hours because the sun rises lower than in summer and the days are much shorter.
Without breaking a record, the situation was also remarkable along the Mediterranean. Nice-Matin evokes, among other things, the almost 24°C reached in Cuers, in the Var. If it has already been 2.5°C warmer this season, the situation remains rare: the thermometer showed +8°C compared to the seasonal norm. In Gard, Hérault, Bouches-du-Rhône and Alpes-Maritimes, similar differences were recorded.
At this time of year, the average temperatures are indeed significantly lower. As Météo France reminds us, at the hottest time of the day, it is normally 11°C in Paris, 14°C in Bordeaux (Gironde), 12.5°C in Brest (Finistère) or 13.5°C in Toulouse (Haute Garonne).
This situation is not without consequences for vegetation and crops. As agro-meteorologist Serge Zaka points out, “after a loss of leaves in summer in response to drought and heat waves, we observed a vegetative recovery favored by the autumn mildness”. He adds that these changes are installed over time and “progressive”. He takes a few examples in support of his demonstration, such as the increasingly early flowering of the Japanese cherry tree or even the advancement of the date of the harvest. In both cases, a very clear acceleration of the phenomenon has been observed over the last few decades.
This Sunday, the observations are similar to the day before. The 20°C are exceeded from the beginning of the afternoon in the North-West. The heat threshold, i.e. 25°C, has even been reached in the South-West, in the Pyrénées-Atlantiques or in Soorts-Hossegor in the Landes.
However, the situation will change significantly on Monday. The rainy days will follow next week over most of the country. The air mass will cool significantly, as shown in this animation.
However, the situation will not be abnormal for mid-November. Temperatures will return to the season. But the contrast between the absence of sun and the drop in temperatures will be marked. Monday, in several regions, they will thus show at least 5°C less compared to this Sunday.