France to face new long heatwave starting Monday

After an early summer heatwave in June, France is about to face another peak in temperatures that will last throughout the coming week. Forecasters have warned that conditions are ripe for forest fires, like the giant blaze in the southern Gard region which firefighters have finally brought under control after three days.

More heatwaves to come. A sunbather sits near a fountain in front of The Louvre Pyramid in Paris on June 17, 2022 (illustration) © AFP

The southwest and the Rhone Valley are the regions most likely to be affected by the new heatwave. 

Although the current temperatures at the weekend were considered to be in line with expectations for the season, Météo France weather agency says this is just the beginning of what is shaping up to be a ten day hot spell, similar to the one in June.

Jean-Yves Choplin, forecaster with the national agency said temperatures close to 40°C would be felt from midweek, particularly in the southwest and the southeast, while the northern half of the country could expect somewhere between 30 and 34°C. 

➡️ Mercredi :
Les plus fortes chaleurs gagnent vers le centre du pays. pic.twitter.com/Ol9lauG7Or

— Météo-France (@meteofrance) July 10, 2022

There are several factors contributing to the gradual rise in temperatures, he explains.

Up until Monday, it has mainly been due to "a fairly powerful anticyclone which covers Eastern Europe and limits air circulation," Choplin told France Info.

"The sun heats this mass of air and the ground during the day, then the air descends again at night, which compresses it and heats it, and so on as long as the anticyclone is maintained". Hence a first phase of slow and generalised rise in temperatures.

From Tuesday, a new phenomenon will come into play: a "cold drop" will form off Portugal.

This mass of cold air which forms at altitude will cause the displacement of a 'tongue' of warm air coming from Morocco.

2+ degrees increase per day

It is this "heat plume", forecast to pass through Spain before hitting the south of France and the Atlantic coast, which will be responsible for the faster rise in temperatures from the middle of the week, with increases of two degrees per day.

Caused by greenhouse gas emissions linked to human activity, "these episodes of strong heat have been much more numerous since 2000", underlines Choplin, who adds that "we experienced two heat waves lasting more than ten days between 1947 and 2000, but already three since 2000".

"This heat wave will be a bit less intense than 2019, but in terms of duration, it's way above that."

It is also necessary to prepare for the potential consequences of this heatwave, in particular fires.

"We will have to be extremely vigilant" Choplin concludes, adding that "there is only a little wind missing next week and all the conditions will be met for forest fires to break out".

Gard 'mega fire' contained

The southern Gard area has already been ravaged by a "megafire" which burned more than 650 hectares.

Up to 950 fire fighters backed by aircraft had deployed but the "critical phase" has now passed, said fire service spokesman Lieutenant Colonel Eric Agrinier on Sunday.

• Hundreds of firefighters, air units battle 'mega' blaze in southern France

"For the moment, the fire is contained. This means that we don't think it can spread anymore," he added.

Around 520 fire fighters remain on the ground in the area, he said, 90 kilometres north of Montpellier and the Mediterranean coast.

The spokesman said units would continue treating the edges of the fire, metre by metre, and were monitoring to avoid any risk of the blaze worsening with temperatures above 30°C, winds and low humidity as risk factors.