National weather agency Meteo France said the heat wave began in the south and is expected to spread across the country and last until the weekend, reports AP.

Overall, the southern half of France expects daytime temperatures of up to 40 degrees Celsius (104 degrees Fahrenheit) and won't drop at night below 20 C (68 F).

The high temperatures aren’t helping firefighters battling a wildfire in the Chartreuse Mountains near the Alps in eastern France, where authorities have evacuated around 140 people.

Meteo France said this week’s heat wave will not be as intense as the one last month, when several regions experienced record-breaking temperatures.

But the high temperatures come during the most severe drought ever recorded, according to the government. Last month was the driest July since measurements began in 1959.

Some French farmers have started to see a drop in production especially in soy, sunflower and corn yields.

Water restrictions in place range from daytime irrigation bans to limiting water usage to people, livestock and to keep aquatic species alive.

The government said last week that more than 100 municipalities can’t provide drinking water through taps and need water truck supplies.

The heat also forced energy giant EDF to temporarily cut power generation at some of its nuclear plants, which use river water to cool reactors.