PARIS (Reuters) – France on Monday afternoon issued a “red alert”, its most serious warning, for four southern regions amid a spell of excessively hot weather, with temperatures expected to peak at 41 degrees Celsius (106 degrees Fahrenheit) in the Rhone valley.

The departments targeted by the alert, which allows local authorities to call off events and close public facilities if needed, are the Rhone, Drome, Ardeche and Haute-Loire, Meteo France said. The alert became effective at 1600 local time.

It was the sixth time the French meteorological service triggered the red alert — part of the government’s programme to protect the population during periods of extreme weather — and the first such incidence this year.

Earlier on Monday, Meteo France had issued an orange alert for half of the country’s territory, saying temperatures will reach between 35 and 38 C (95 to 100 F) in most of the affected departments. Peaks of 41 Celsius were expected in the southwest and in the Rhone valley.

Temperatures are expected to rise to between 40 and 42 Celsius (104 and 108 F) on Tuesday afternoon in the southern departments of Ardeche, Drome, Vaucluse and Gard, Meteo France said.

Separately, French power company EDF said it extended the outage at its 1.3-gigawatt Golfech 2 nuclear reactor in south-western France on Monday because river water used to cool the reactor had surpassed maximum temperatures due to the heatwave.

Some technical issues at the reactor also played a role in delaying the restart to Aug. 25, an EDF spokesperson told Reuters. The reactor has been offline since March 27 and had been scheduled to restart on Sunday.

Water temperature levels for cooling purposes at the Bugey plant and another reactor along the Rhone river in the southeast were also seen surpassing the government’s guidance by Aug. 24, Refinitiv data showed. EDF had previously announced production warnings at the Bugey plant.

(Reporting by Forrest Crellin; Dominique VidalonWriting by Tassilo Hummel; Editing by Sudip Kar-Gupta, Emelia Sithole-Matarise and Jonathan Oatis)

FILE PHOTO: The logo of Electricite de France (EDF) is seen in front of electrical pylons at the Tricastin nuclear power plant site in Saint-Paul-Trois-Chateaux, France, November 21, 2022. REUTERS/Eric Gaillard/File Photo