High temperatures across Europe this week broke records, leading to the closure of nearly 2,000 schools in France at midday on Tuesday.

"June 2025 has become the second hottest June since records began in 1900, behind June 2003," Ecology Minister Agnes Pannier-Runacher said on Wednesday.

Temperatures in June 2025 were 3.3 degrees Celsius higher than the seasonal average compared to 3.6 degrees Celsius in June 2003, her office said.

"More than 300 people have been treated by firefighters and two have died following heat-related illnesses," Pannier-Runacher added.

Her office later clarified that the two deaths were not an official confirmation of the death toll but based on information from media reports.

France's Health Minister Catherine Vautrin confirmed it was "too early to take stock" of the consequences of the heatwave.

"What I can say is that yesterday we saw an increase in emergency services activity in the Ile-de-France region, a serious increase of 15 percent," Vautrin said, speaking on television broadcaster BFMTV on Wednesday.

The health ministry said that an initial estimate of excess mortality during the heatwave will be published around two weeks after it comes to an end.

But a detailed report showing the number of deaths linked to the soaring temperatures with medical data will not be available until the autumn, it added.

Around 3,700 heat-related deaths were reported in 2024, a year without red alerts for heatwaves.

In 2023, which saw hotter summer temperatures, more than 5,000 deaths linked to heat were recorded.

Relief will start to arrive from the Atlantic on Wednesday, bringing thunderstorms and cooler temperatures to parts of western Europe.