A girl gets water doused on her by her father as heatwave continued to affect the European countries. AFP

The severe heat, which forecasters say will only last a few days but will be exceptionally intense, is expected to affect northern France and parts of Belgium, Luxembourg and the Netherlands.

Temperatures were already set to top 30˚C on Monday in Paris, but the mercury could soar beyond 40˚C on Thursday and topple a temperature record dating back to 1947.

People enjoy refreshing water of a fountain in a park. AFP

"It's likely that these three countries see temperatures at or above 40˚C for the first time," Francois Jobard, a forecaster from the French Meteo France weather office, told AFP.

The new blast of hot air comes less than a month after a heatwave scorched Europe at the end of June, forcing new attention on the issue of climate change.

"The heatwave that is too much," said the headline in the Le Parisien daily on Monday, highlighting that "Act II" of this summer's severe weather would further hurt production of crops from potatoes to grapes.

"Thursday (July 25) will be a potentially historically hot day," added Jobard from Meteo France.

"We are forecasting 41 or 42 degrees in Paris on Thursday and there is the strong chance of beating the record," he added.

The highest ever temperature recorded in Paris was 40.41˚C in 1947. Since records began in 1873, this was the only time a plus-40 temperature was recorded in the French capital, he said.

Other French cities could also see their all time records tumble on Thursday including Reims, Bourges, Lille and Clermont Ferrand, he said.

Britain will also see high temperatures, but will still be significantly cooler than countries on the continent.

Forecasters predict there is a chance the 36.7˚C record high for July — set on July 1, 2015 at London Heathrow Airport — could be broken.

Germany was already experiencing several forest fires and drying river beds while farmers fear another bad crop after last year's low yield which was also caused by an unusually hot summer.

The French government has warned that wine production will be down by between six to 13 percent over 2018, notably because of the ongoing heatwave.

Huge wildfires that have ravaged the mountainous Castelo Branco region of central Portugal and left dozens injured have been "90 percent" controlled, firefighters said Monday, but warned that strong winds could cause the flames to spread.

Agence France-Presse