Weather: what you need to know about the arrival of an exceptional heat wave in France

Europe 1 with AFP 8:54 p.m., June 13, 2022

France will experience temperatures well above 30°C this week, a particularly early heat wave, yet another foretaste of a warming planet, in a context of exceptional dryness of the soil which raises fears of crop losses. and fires in France.

A temperature of 30°C everywhere, peaks at 40°C

A localized depression between the Azores and Madeira gradually brings very hot air from the Maghreb to Western Europe.

The Iberian Peninsula is already affected, with temperatures of more than 40°C expected, especially in Spain.

This hot air will arrive in France on Tuesday from the South-West before spreading first over the entire southern half on Wednesday and then north.

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Already on Monday, records were recorded, particularly across France with a peak for 2022 at 37.6°C recorded in Cuers in the Var.

For the southern half, the peak will be Thursday, Friday and Saturday, with 35 to 39°C, or even 40°C locally, probably in the Southwest, Frédéric Nathan, forecaster at Météo France, told AFP.

If this episode could be shorter in the North, the mercury could still reach around 35°C on Friday in Rennes or Paris.

It will be hot everywhere on Saturday (between 34 and 38°C) before thunderstorms expected on Sunday.

Earliest heat wave

The country has already experienced exceptional temperatures in June.

The absolute record for mainland France dates from June 2019, with 46°C in Vérargues (Hérault) but it was at the very end of the month (June 28).

This heat wave would be "a priori, on a national scale, the earliest since the start of the measurements", indicates the forecaster.

The previous one dates from 2017, from June 18 to 22 (localized heat waves occurred earlier in June in Alsace or Aquitaine in 2003).

A clear sign of global warming

Heat waves and heat waves are the clearest signs of global warming caused by human activities.

Many scientists no longer hesitate to say that climate change is partly responsible for all these heat waves.

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In France, these episodes have accelerated over the past 30 years and this is only the beginning: even in an optimistic scenario of a massive reduction in greenhouse gas emissions, the annual number of days of heat waves or heat waves are expected to double by the end of the century.

"We are living a foretaste of our climatic future," summed up climatologist Christophe Cassou on Twitter.

Heat wave or heat wave?

A heat wave corresponds to abnormally high temperatures for several consecutive days, with thresholds that vary by region.

For France, the national thermal indicator (a sort of national average) must exceed 25.3°C for three days in a row.

We speak of a heat wave when a wave "represents a danger for the population in terms of excess mortality", explains to AFP Sylvain Mondon, from Météo-France.

A risk estimated by department from average maximum and minimum temperatures (at night) over three days.

Météo France is currently forecasting a "heat wave" but considers it likely that the "heat wave" threshold will be reached in certain departments, with minimums above 20°C at night.

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A particularly warm spring

This heat wave comes after a particularly hot and dry spring which caused drought in much of France, raising fears for crops and creating conditions conducive to fires.

On June 1, the soil moisture index reached a value usually seen in mid-July.

The thunderstorms in early June improved things slightly, but the situation deteriorated further in certain regions, notably the South-East.

In this context, 35 departments have implemented water use restrictions.

On Monday, the Gard experienced several major fire outbreaks, including burning 60 bungalows in one of the largest campsites in Europe.