Temperatures continue to rise in France: 19 departments are now placed on heatwave red alert on Wednesday August 23 on a diagonal from Gers to Ain and 37 others in orange. An episode described as “intense” and “sustainable”, even “exceptional” in certain localities, by Météo-France.
Tuesday afternoon, fifteen departments were added to the four already in red – Ardèche, Drôme, Haute-Loire and Rhône – bringing the total number of departments on maximum alert to 19, according to Météo-France. These are Ain, Loire, Isère, Lozère, Gard, Vaucluse, Hérault, Aveyron, Tarn, Tarn-et-Garonne, ‘Aude, Lot, Lot-et-Garonne, Haute-Garonne and Gers. An “already remarkable” temperature of 43°C was measured in Puy-Saint-Martin, in Drôme.
“A long-lasting and intense heat wave has settled over the southern two-thirds of the country. It takes on a remarkable or even exceptional character right now in the Rhône Valley and in the south of the Massif Central, then gradually in Occitania and as far as the west of Aquitaine tomorrow, ”notes Météo-France.
The maximum temperatures will reach 40 to 42 degrees there, or even more locally, with probable records at the key, warns the meteorological service.
Some 37 departments, still in the southern two-thirds of the country, are on orange alert, under a line running from Vendée to Bas-Rhin.
“The heat wave peak is expected between today [Wednesday] and Thursday”, according to the forecaster, stressing that vigilance in certain departments, “especially in the south of New Aquitaine”, could increase in the face of the duration and the intensity of the heat wave. “Across France, this is the first time that such an intense heat wave has been observed so late in the summer,” adds Météo France.
On Monday, the country experienced its hottest day ever measured after August 15, with a national thermal indicator of 26.63°C. This value is 5.8°C above the normal for the season over the period 1991-2020, the public establishment explained to Agence France-Presse.
Differentiated traffic in Marseille
As a result of this heat wave, air quality has deteriorated in Marseille where differentiated traffic will be put in place on Wednesday. The most polluting vehicles will not be able to drive in the city center, the prefecture announced on Tuesday.
“Differentiated traffic is in place from Wednesday, August 23, 2023” at 6 a.m. and “until further notice,” she said in a statement. Only vehicles with green Crit’Air vignettes or ranging from 1 to 3 will be able to circulate within the perimeter concerned by this measure, i.e. most of the center of the second largest city in France.
Due to rising ozone concentrations in the air, four departments in southeastern France – Vaucluse, Bouches-du-Rhône, Var and Alpes-Maritimes – will go into level 2 alert on Wednesday, corresponding to “enhanced vigilance for all public”.
“The implementation of differentiated traffic is accompanied by emergency measures” aimed at “reducing pollutant emissions”, recalls the prefecture, citing in particular the 20 km/h reduction in traffic speed on all roads of the department (without however going below 70 km / h) or even the electrical connection to the quay of ships “within the limits of the available installations”.
On Wednesday, the minimum temperatures will be around 20 to 25 ° C in the regions affected by the heat wave, 26-27 ° C around the Mediterranean. As for highs, 37 to 40°C are expected over most of the southern half, with higher peaks locally. According to Météo-France, the decline will begin by the West on Friday.
Only a last northern quarter is still spared by the heat wave. From Brittany and north of the Loire to the Benelux, the minimums will range from 13 to 18 ° C in general. In the afternoon, the thermometer will show between 28 and 34°C.