40°C in the north and 42°C in the south: the heat wave is more intense and longer than expected

This Thursday, at 2:48 p.m., the 40.2 ° C bar was crossed for the first time this year in the Aude at Argeliers. This is the earliest 40°C recorded in mainland France, apart from Corsica which already recorded a temperature of 40°C on June 14, 2019 in Ajaccio. Weather report France triggered this Thursday afternoon a red alert for twelve departments in the west of the country, unheard of in the month of June: Tarn, Haute-Garonne, Gers, Tarn-et-Garonne, Lot-et-Garonne, Landes, Gironde, Charente, Charente-Maritime, Deux-Sèvres, Vienne and Vendée.

Twenty-five other departments are on orange alert. Of the minimum and maximum temperature records for a month of June should be beaten on Friday and Saturday. The next two nights, the minimums in the departments in orange and red vigilance, will be between 20 and 25°C, very high values ​​for the season.

Absolute records expected in some cities

The heat will indeed be stronger than expected this Friday and Saturday, with the 40°C threshold which will be frequently reached, and even exceeded, over a large south-west quarter: locally, temperatures may rise to 42°C in this zone. But the danger will also be taken very seriously in the north, where the symbolic cap of 40°C could also be reached! In Paris, the mercury should rise to 39°C on Saturday, or even more. More than monthly records, absolute heat records may be broken in certain cities.

A possibly violent stormy deterioration is expected on Sunday in the west, and should allow a drop in temperatures. But, in the southwest, the end of the high heat seems to be moving away and will perhaps be postponed until Tuesday.

The earliest heat wave ever observed in France sets in for the week

Article of Karine Durandwritten on June 14, 2022

An episode of heat wave intense and early will affect the west and south of France: temperatures will reach or even exceed 40°C between Wednesday and Saturday. This should be the earliest heatwave episode ever observed in France.

Since last weekend, a cold drop in the Azores has brought heat to Spain and Portugal. The depression is driving a southerly flow that sucks theair from North Africa to propel it towards Europe: this is the mechanism of heat pump. Morocco and Spain faced scorching temperatures last weekend, with up to 42°C in Seville, Andalusia. Highs of 45°C or even 46°C are possible in Morocco these days. In France, the heat has already started to increase in recent days, with 36 ° C recorded in Nîmes this Sunday, and 37 ° C recorded in Hérault and Vaucluse.

The heat peak is expected on Friday

This “heat feather”, as the meteorologists, will lead to an episode of very hot weather over almost all of France between Wednesday and Saturday. The hot air centered on Spain will rise towards our country, starting with the southwest on Tuesday, then towards the north on Wednesday and then the east. The heat peak will be reached between Thursday and Saturday, the hottest day being forecast for Friday, with temperatures exceeding the seasonal average by 10 to 15°C! The values ​​can go up to:

• 35/36°C in Paris (against a normal of 24°C);
• 40°C in Biarritz (against 23°C);
• 39/40°C in Toulouse (against 25°C);
• 30/32°C in Lille (against 21°C);
• 35°C in Perpignan (against 26°C);
• 36°C in Montélimar (against 26°C);
• 32°C in Brest (against 19°C).

Particularities of this exceptional episode, the heat will reach usually cooler areas such as Brittany (over 30°C over almost the entire region), monthly records may be broken and the official heat wave thresholds will be a priori exceeded in some departments.

Heatwave thresholds may never have been reached so soon

Meteo France defines a heatwave as ” an episode of high temperatures, day or night, over an extended period. As part of meteorological vigilance, account is taken of the exceptional nature of nighttime temperatures. When these are high for several consecutive days, the risk of mortality increases in frail people. Daytime and nighttime temperature thresholds are set for each region. The heat wave is therefore a question of temperatures but also of duration (more than three days). This week, several departments in the south-west should officially enter the heat wave thresholds, with temperatures exceeding 35°C during the day and 20°C at night: these thresholds will be reached for four to five days locally. On the northern half, the thresholds should not be reached for more than two days, even if uncertainty remains about the end of the period, linked to the arrival ofthunderstorms over the weekend.

The heat waves affect France almost every summer, mainly between early July and mid-August, but they can sometimes occur outside this period. The appearance of heat waves in June is moreover a phenomenon that tends to occur more and more for 20 years. Météo France specifies that France already experienced a heat wave in June 2017 remarkable for its precocity and intensity: since 1947, only the heat wave from June 18 to 28, 2005 had been so early and never had a day in June been so hot since the start of Météo-France readings ». Another more recent heat wave, end of June 2019which was marked by the day of June 27, the hottest day recorded in the month of June, with an average temperature in France of 27.9 ° C.

However, the last three major reference heat waves in June (2005, 2017 and 2019) occurred after June 18, that of 2022 starting on June 15 and ending, a priori June 18. If the heat forecasts continue to be confirmed, France could therefore experience its earliest heat wave ever observed since the start of weather records.