Monuments in Paris are working on reduced hours, and dozens of people in France have drowned during the heat wave. Britain, France, Italy and Spain have issued red alerts and health warnings.

France's national weather agency, Meteo-France, said Tuesday was the hottest day ever recorded since 1947, with the average of daytime and nighttime temperatures across 30 stations reaching 29.8 degrees Celsius (85.6° F), according to provisional data.

Daytime highs above 40° C (104° F) were also recorded in many individual weather stations, the agency added.

This included preliminary readings of 44.3 degrees Celsius in the Atlantic coast town of Pissos on Tuesday afternoon.

The previous record of 29.4°C (84.9°F) dated back to heat waves of August 2003 and July 2019.

The record-breaking day comes after the hottest night France has experienced since record-keeping began in 1947, according to an X post from Meteo-France earlier Tuesday.

The night from Monday into Tuesday saw the average temperature compiled from 30 record-keeping stations reach 21.6 degrees Celsius (70.8 F).

"As of noon this Tuesday, 54 departments are under a red heatwave alert—another unprecedented situation," the post said.

According to Prime Minister Sebastien Lecornu, 40 people have drowned since the heat wave set in on Thursday, many of them minors.

Louvre reduces hours due to extreme heat
The Louvre Museum will reduce its operating hours due to the heat wave in Paris.

From Tuesday until Saturday, the famed art gallery will close two hours early at 4 p.m.

"Due to the extremely high temperatures starting [...] we encourage you to adjust the pace of your visit and protect yourself from the heat," the museum said in a statement.

"Take your time, wear light clothing, and stay hydrated!"

The museum added: "Some galleries may be closed during the heat wave to protect the artworks."