The situation will improve on Sunday, but the temperatures will remain very high the following days.
38 degrees in the shade in Nantes and Rennes, 40 ° C in Paris, 39 ° C in La Rochelle… Historic temperatures for the month of June are expected on Saturday during the paroxysm of the heat wave in France. “Absolute records could even be reached locally, exceeding the maximums recorded during the summer heat waves of 2003 and 2019”, underlines Régis Crépet, meteorologist at the Weather Channel (Figaro group). The 40 ° C bar was passed on Thursday in Saint-Jean-de-Minervois, in Hérault, for the first time so early in mainland France. Saturday is expected to be the hottest day on record in June, with a day-night average of 28°C nationwide.
Fourteen departments have been placed on red alert by the Weather Channel, and 53 on orange. The west of the country will experience a second day of furnace, with possible peaks at 42 ° C, or even 43 ° C locally in New Aquitaine for example. The heat wave will gradually spread north and east, eventually overwhelming the entire territory. “The intensity of the expected temperatures prompted us, in conjunction with Public Health France, to trigger heat wave vigilance even if the episode lasts only 48 hours in certain regions”, underlines François Jobard, forecaster at Météo-France. The alert is normally issued when temperatures reach 34°C during the day and do not drop below 20°C at night, for three days in a row.
Prolonged extreme heat is dangerous for the body, especially if it has not been able to recover due to the night mildness. But the night from Friday to Saturday was to be the hottest of the episode. The day before, a temperature of 25°C had already been recorded in Toulouse at the coolest moment, that is to say at dawn.
Even if uncertainties still exist, meteorologists predict a gradual end to the heat wave from Sunday. The weather will cool off from the northwest from Saturday evening
Recalling the risks of fatigue, heatstroke, dehydration and decompensation of existing illnesses, the health authorities have urged the population to be cautious, and to protect fragile people (infants, children, pregnant women and over 65s). A toll-free number
has been set up. Especially since the heat will be accompanied by an episode of ozone pollution in Île-de-France, as well as in several departments of Occitanie, Paca and Hauts-de-France.
Heatwave: 14 departments placed on red alert
Even if uncertainties still exist, meteorologists predict a gradual end to the heat wave from Sunday. The weather will cool off in the northwest from Saturday evening. The wind will pick up and the mercury will then drop to around 30°C in the north and west of the country. Still above seasonal norms, but below heat wave alert thresholds. The night will be less suffocating than the previous ones. However, the heat should still resist a little in the eastern and central regions, which may experience peaks of 35 ° C on Monday. The exit from this heat wave event could be accompanied by strong thunderstorms.“They could be virulent from time to time, but they will remain localized because the soils are very dry, which limits evapotranspiration”
The cities most threatened by the explosion in the number of heat wave days and nights
The heat wave also aggravates the dryness of the soil and increases the risk of fire starting everywhere in France. It also has consequences in agriculture, especially for aquatic ecosystems and wild animals (in the midst of reproduction and feeding of the young). Some species of birds, such as passerines for example, abandon their nests when the air temperature is too high, leaving their chicks to die. While the bees exhaust themselves ventilating their hives, thus losing strength that will not be dedicated to foraging.
* Hotline toll-free number, from 9 a.m. to 7 p.m.: 0800.06.66.66
The increasingly frequent heat waves in France
Global warming makes heat waves comparable to the one France is currently experiencing more and more likely. From a simple statistical point of view, the 1.2°C warming recorded by the planet since the beginning of the industrial era reduces the risk of having temperatures above 35°C for more than three days in Paris region between June 16 and 18, from once every 100 years to once every 10 years. More specifically, climate models predict an increase in summer heat waves in France, to such an extent that in 2050 a summer heat wave like that of 2003 would occur every other year. The models also allow us to say that the current heat wave, carried by a bubble of hot air coming from the Sahara, would have caused temperatures of 2°C less without the warming. The increase in the frequency of heat waves is very visible in French climate records since 1947. Before 1990, there were an average of two events of this type per decade, while 17 were recorded between 2010 and 2019!