Europe 1 with AFP / Photo credit: LILIAN CAZABET / HANS LUCAS VIA AFP 11:50 am, September 08, 2023

"This is the first time that an orange heatwave vigilance is triggered beyond the summer period, since the implementation of vigilance for this phenomenon in 2004," said Météo-France. Since Wednesday, "a weak wind prevents the dispersion of pollution" in Ile-de-France, no "frank" improvement is to be expected before the beginning of next week.

"I am swimming": 14 departments of Ile-de-France and Centre-Val de Loire are on alert orange heatwave from Friday to Saturday, an unprecedented heat episode so late in the year and which contributes to generate significant air pollution in Paris.

The French have had a strange back-to-school week, from children sweating in their classrooms to winemakers forced to harvest at night. The opening match of the Rugby World Cup, Friday night in Saint-Denis, will therefore be played in a warm atmosphere, with 28 ° C in the evening, and polluted, after a week where Paris has experienced more than 30 ° C each day, as in many regions of France.

Unbearable heat in the subway

"Look, I barely walked for a few minutes and I'm already swimming," says Pascale Guyon, a 64-year-old retiree who no longer goes out without her water bottle. At home, in the town of Charenton-le-Pont east of Paris, it is impossible to make drafts and in the metro the heat is unbearable. Khadija, a social worker, agrees: "Between (professional, editor's note) trips on foot and public transport it is very difficult, even unbearable".

Maximum temperatures will reach 33 to 36 degrees, with peaks at 37 in Centre-Val de Loire, where monthly records of maximum temperatures under shelter have already been observed on Thursday. In Orleans, capital of the region, the four museums of the city are open free of charge Friday so that the population "enjoys the freshness in a cultural setting," announced the town hall. And night temperatures will even rise, according to Météo-France. An exceptional continuation of the fourth hottest summer ever measured in France, and the hottest globally.

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'Significant drop' on Monday

On Sunday, temperatures are expected to remain high "although possibly slightly decreasing, before a more significant drop from Monday," said the forecaster Friday morning, after extending the orange vigilance until Saturday. "This is the first time that an orange heatwave vigilance is triggered beyond the summer period, since the implementation of vigilance for this phenomenon in 2004," said Météo-France.

According to climatologists, human-induced global warming makes heat waves more frequent and severe, but also earlier and later. Some 36 other departments, mostly in the northern half of the country, are on yellow alert, which has led to an increase in pollution levels in several regions. Several prefectures, including that of Paris, have reduced the speed of traffic and banned open burning, without triggering differentiated traffic.

High heat and sunlight react with car and truck exhaust and volatile organic compounds to generate ozone, a harmful gas at low altitudes that causes respiratory problems and asthma attacks.

Ozone hazard

For Sidibé, a mover met by AFP in Charenton-le-Pont on the way to his children's nursery, "it's horrible". "I go back and forth to the fifth floor to lower furniture or fridges without an elevator! When it's too hot like that, it prevents me from breathing," adds the 36-year-old who already has "breathing difficulties". Since Wednesday, "a weak wind prevents the dispersion of pollution" in Ile-de-France, according to the organization Airparif, which believes that no improvement "frank" is to be expected before the beginning of next week.

This episode "so late in the summer season is rare," adds this regional association for air quality monitoring, stressing "the close links between air pollution and climate change". Several departments of Hauts-de-France and Brittany are facing an episode of pollution with PM10 particles (diameter less than 10 microns, often generated by construction sites, heating and factories), with speed reductions at the key. In the Southwest, it was the sand dust from the Sahara brought by the wind that pushed the authorities to raise the alert level.

In Sens, in the Yonne, the heat could have contributed to the death of a 37-year-old police officer on Thursday during a day of off-road motorcycle training but other hypotheses are being considered, according to the city's National Police Academy and several police union sources.