A heatwave sweeping southern Europe that has caused hundreds of deaths and huge wildfires showed some signs of abating today but continued to move north, including towards Britain where authorities issued an extreme weather warning.

Much of Europe is baking in a heatwave that scientists say is consistent with climate change and has pushed temperatures into the mid-40s Celsius in some regions, with wildfires raging across tinder-dry countryside in Portugal, Spain and France.

A host of towns and cities in France recorded their highest ever today, according to the country's national weather service.

"In some southwestern areas, it will be a heat apocalypse," meteorologist Francois Gourand told AFP.

French firefighters were struggling to contain two massive fires in France's southwest that have created apocalyptic scenes of destruction.

For six days, armies of firefighters and a fleet of waterbombing aircraft have struggled against blazes that have mobilised much of France's entire firefighting capacity.

Forecasters have put 15 French departments on the highest state of alert for extreme temperatures, including in the western Brittany region where the Atlantic coastal city of Brest was expected to hit 40C today - nearly twice its usual July temperature average.

Despite temperatures easing in some parts of southern Europe over the weekend, thousands of firefighters across the region still battled to contain hundreds of wildfires and authorities said the risk of further blazes remained extremely high.

Spain was facing the eighth and last day of a more than week-long heatwave today, which caused more than 510 heat-related deaths, according to estimates from the Carlos III Health Institute.

With fires burning thousands of hectares in Galicia, Castille and Leon, Catalonia, Extremadura and Andalusia, Spain mourned the death of one firefighter in the northwestern province of Zamora yesterday evening. Almost the entire country faces an extreme fire risk.

In El Pont de Vilomara in Catalonia, evacuees gathered outside a civic centre, among them retiree Onofre Munoz, 69, who said that his home and van had been completely destroyed.

"We bought the van when I retired and now it's totally scorched. We have nothing," he said.

Dense smoke and flames of the Pont de Vilomara fire in Sant Fruitos del Bages, Barcelona

Our house had quite a few windows, they exploded, and a powerful flame came inside. We knew it yesterday afternoon because we got some pictures in which we saw everything had burned."

More than 70,000 hectares have burnt in Spain so far this year, the worst year of the last decade, according to official data. Last month, a huge wildfire in Sierra de la Culebra, Castille and Leon, ravaged about 30,000 hectares of land.

Spain also reported a second death caused by a wildfire after a fireman died yesterday.

A 69-year-old was found dead today in Ferreruela, in an area burned by flames, emergency authorities said. Local media said it was a farmer.

In Portugal, temperatures dropped over the weekend, but the risk of wildfires remained very high across most of the country, according to the Portuguese Institute of Meteorology.

More than 1,000 firefighters, backed by 285 vehicles and 14 aircraft, were battling nine ongoing wildfires, mainly in the country's northern regions, authorities said.

European Commission researchers meanwhile said that 46% of EU territory was exposed to warning-level drought.

11% was at an alert level and crops were already suffering from lack of water.

National emergencies

Belgium and Germany were among the countries expecting the heatwave to hit them in coming days.

The EU said it was monitoring closely wildfires raging in southern member states today, sending a firefighting plane to Slovenia over the weekend adding to recent deployments to France and Portugal.

"We continue of course to monitor the situation during this unprecedented heatwave and will continue to mobilise support as needed," spokesperson Balazs Ujvari told a briefing.

The EU was also providing satellite imagery to France, he added. Separately, the Commission announced in a report that almost half the territory of the bloc was currently at risk of drought.

Britain was on course for its hottest day on record today with temperatures forecast to hit 40 Celsius for the first time, forcing train companies to cancel services, schools to close early and ministers to urge the public to stay at home.

The government has triggered a "national emergency" alert as temperatures were forecast today and tomorrow to surpass the 38.7C recorded in the Cambridge University Botanic Garden in 2019.

An extreme temperature warning was issued by the UK Met Office

"We hoped we wouldn't get to this situation but for the first time ever we are forecasting greater than 40C in the UK," climate attribution scientist at the Met Office, Dr Nikos Christidis, said.

"Climate change has already influenced the likelihood of temperature extremes in the UK. The chances of seeing 40C days in the UK could be as much as ten times more likely in the current climate than under a natural climate unaffected by human influence," he said.

In the Gironde region in southwestern France, the fires had destroyed 14,800 hectares, local authorities said today. More than 14,000 people have been evacuated from the area. France has issued red alerts, the highest possible, for several regions, with residents urged "to be extremely vigilant".

In Italy, where smaller fires have blazed in recent days, forecasters expect temperatures above 40C in several regions incoming days.

Switzerland also suffered the effects of the heatwave. Axpo, the operator of the Beznau nuclear plant, said it was today forced to reduce output so that it does not overheat the Aare river from which it draws its cooling water.

The Swiss government issued a heat wave advisory, citing considerable danger across much of the country with temperatures in some parts reaching 36C.