PARIS – More than three-quarters of France’s population will experience extreme heat today as authorities issue red alerts across 35 departments and ban alcohol at the country’s annual music festival.

The severe heatwave, which began earlier this week, has disrupted the country, forcing the cancellation of dozens of trains and the suspension of classes.

Authorities have expressed concern about how the annual Fête de la Musique celebrations will unfold across the country on Sunday 21 June, when musicians perform free concerts in the streets and crowds gather late into the night.

Météo-France announced the highest heatwave warning for 35 of France’s departments for today, the most ever issued. The weather service said very high temperatures were settling across the country for an extended period.

Starting tomorrow, temperatures could reach 41°C in some areas, and the average reading across the whole country could reach its highest ever, Météo-France predicted. The duration of the heatwave remains uncertain.

Paris is among the regions on the red alert list, which covers a wide area running south-west from the capital.

According to calculations, more than three-quarters of the mainland’s population will experience extreme heat, with another 45 departments under orange alert.

The government announced on Saturday that alcohol consumption during the annual street festivals would be banned in departments under red alert.

“Prefects will issue decrees banning alcohol consumption in public spaces in the departments under red alert,” the government said in a statement following a meeting chaired by Prime Minister Sébastien Lecornu.

His office said instructions had been given not to offer alcohol at events organised by the state and its agencies.

The government has called for limits on alcohol consumption “to preserve emergency and healthcare services and allow medical staff to focus on caring for the most vulnerable”.

To help Parisians and tourists cope with the heat, authorities are keeping parks and gardens in the capital open through the night.