Heatwave 2023: 50 departments on orange alert, where will it be the hottest?

HEAT 2023.

Heatwave 2023: 50 departments on orange alert, where will it be the hottest?

HEAT 2023. 50 departments are placed on orange alert this Monday, August 21, the heat wave is hitting the entire southern half of France where up to 40°C are expected.

[Updated on August 21, 2023 at 8:16 a.m.] It is a "lasting and intense" heat wave that is beating down on France. 49 departments were already placed in orange vigilance in the face of the heat, there are 50 this Monday, August 21. Charente-Maritime is added to the list of affected territories. And the heat wave could last until the middle of the week according to the forecasts of Météo-France which announces a heat wave peak around Wednesday and "temperatures which can still remain very hot on Thursday". So much so that heat records could (again) be broken with 40 or even 42° degrees expected, especially in the Rhône Valley. 14 other departments are on yellow alert.

Red vigilance could be activated during this late heat wave warns Météo-France, especially in the south-east of the country. The meteorological agency quotes the Drôme, the Ardèche but also the Vaucluse and the Gard. The change from orange to red vigilance could be confirmed in the bulletin expected at 4 p.m. on Monday.

The entire southern half of the country and part of the east are in the grip of the heat wave. 50 departments are placed on orange alert: Gers, Lot, Lot-et-Garonne, Tarn, Tarn-et-Garonne, Allier, Cantal, Puy-de-Dôme, Doubs, Jura, Saône-et-Loire, Corrèze and Rhône, Isère, Ain, Savoie, Haute-Savoie, Loire and Haute-Loire had already been on orange alert for a few days. The Territoire-de-Belfort, Haute-Saône, Côte-d'Or, Nièvre, Drôme, Ardèche, Aveyron and Haute-Garonne were added on Friday August 18. Sunday morning, the departments of Haut-Rhin, Cher, Indre, Charente, Haute-Vienne, Dordogne, Gironde, Landes, Ariège, Pyrénées-Orientales, Aude, Hérault , Gard, Lozère, Vaucluse, Bouches-du-Rhône, Var, Alpes-de-Haute-Provence, Hautes-Alpes, Alpes-Maritimes and Haute-Corse as well as Andorra are also placed in orange vigilance. Since Monday, August 21, a fiftieth department, Charente-Maritime, has been placed on orange alert.

At the hottest of the afternoon, it will be 39°C in Toulouse, 40°C in Castres and 42°C in Alès according to meteorologist forecasts. 35°C degrees are expected in Marseille and "it will be locally 41°C in the shade, especially between Drôme, Ardèche, northern Gard and Vaucluse", can we read in the day's weather report.

The cities with the highest temperatures recorded this Sunday, August 20:

It was between 35°C and 37.2°C in Brive, Mâcon, Mont-de-Marsan, Villeneuve-sur-lot and Lyon-Bron. 38.4°C were reached in Toulouse-Blagnac, 38.8°C in Mende, 39.6°C in Albi, 39.8°C in Sisteron. In places, the mercury even exceeded the 40°C mark: 40.3 in Carcassonne, 40.8 in Aubenas, 41 in Nîmes, 41.8 in Orange, 42.2°C in Salindres (Gard) and Grospierres (Ardèche).

While France is experiencing the "hottest summer 2023" heatwave episode according to Météo-France, the government has decided to activate the national telephone platform Canicule info service, the Ministry of Health announced in a press release. by France Bleu. A decision taken at the end of an interministerial crisis unit organized on August 17 at the initiative of the Prime Minister. This green number can be reached from 0800 06 66 66, and is open from 9 a.m. to 7 p.m. The Ministry of Health indicates that this number “allows you to obtain advice to protect yourself and those around you, in particular the most fragile, and to adopt the right reflexes in the event of high heat”. In addition to the activation of this platform, prevention messages are also broadcast on television and radio, says Les Echos.

As a reminder, we speak of a heat wave when these four characteristics are combined:

On June 8, 2023, the government announced the various actions implemented as part of its heat wave plan to protect the population during intense heat waves.

Heat wave and heat wave are two different things. To speak of a heat wave, the temperatures must be five degrees higher than normal for the season, day and night, and this for at least three days and three nights. The heat wave temperature threshold therefore differs according to the departments and regions. Heat waves most often occur in France in July and August. We must be vigilant from the month of June. High temperatures, even above seasonal norms, do not necessarily mean a heat wave. Most often, these are heat waves.

The term heat peak is more to be used during a sudden rise in temperature, whereas a heat wave corresponds to a longer episode. Météo France judges that a heat wave is in progress when temperatures above the monthly average are detected by more than three degrees Celsius, for at least three days.

Finally, heat dome is another term used. It settled over almost all of France in May 2022. This meteorological phenomenon is explained by a large mass of hot air from Morocco and Spain, trapped by atmospheric pressure. This usually occurs in summer, but also in spring. It results in scorching heat.

Météo France provides several levels of heatwave vigilance: level 1 (green) corresponds to a "seasonal watch", level 2 (yellow) to a "heat warning" and it is level 3 (orange) which corresponds to "the 'heat wave alert'. Finally, level 4 (red), the highest, determines "maximum mobilization". In summer, it is not uncommon for several departments to be placed on orange or red alert for the heat wave.

If the heat wave of the summer of 2003 remains in all memories (and that of 1976 also among the old), France has since experienced other episodes of very hot weather. In summer 2019, several absolute temperature records were reached in different cities. According to data from Météo France, 50 cities had set a new record since July 25, 2019. While the summer of 2019 had been very hot, some records were broken during the heat wave of mid-June 2022. During the day heat wave of Saturday June 18, 2022: 150 municipalities broke a heat record, according to meteorologist Patrick Marlière, interviewed by BFM TV: "We went from 70 cities with broken monthly records, to more than 150 today in France, from the Pyrenees to the Belgian border". The city of Nantes thus broke its record for the month of June with 39.1°C. In the South-West, records at over 40 degrees have been reached: Biarritz with 42.9°, Saint-Jean-de-Luz with 42° or Bordeaux with 40°.

The July 2022 heat wave also set temperature records on Monday July 18. Of the 63 records recorded that day, the majority are in the north, west or southwest. We can cite :