Photo: The Canadian Press

Potatoes are harvested on a dry acre in Frankfurt, Germany, Thursday.

Hot air from Africa is bringing a new heatwave to Europe, prompting health warnings about Sahara Desert dust and exceptionally high temperatures that are forecast to peak at 47 C in some southern areas.

The torrid weather meant public services were put on alert in the Iberian peninsula, where temperatures were forecast to reach 44 C Thursday in the Portuguese city of Evora.

A hot air mass was moving northward from Africa, authorities said, warning that the mercury could peak at 47 C this weekend in some areas of southern Portugal.

Portuguese authorities issued a nationwide health warning, including for dust from the Sahara Desert. Warnings were also issued for 40 of Spain's 50 provinces. The southeastern Portuguese town of Beja is expected to see a peak of 47 C on Saturday.

Up north in Sweden, the country's official tallest point is set to change amid record temperatures.

Scientists said a glacier on Kebnekaise mountain, the Scandinavian country's highest peak at 2,111 metres, is melting and is no longer Sweden's tallest point.

Gunhild Rosqvist, a Stockholm University professor in geography, said the glacier lost four metres of snow in July alone as Sweden endured record temperatures that triggered dozens of wildfires, even in the Arctic Circle.

In eastern Europe, Poland was also enduring unusually high temperatures as the hot African air pushed temperatures up to 34 C.

The country's power plants went into emergency mode to increase output due to wide use of air conditioning and electric fans. Authorities in Warsaw placed cooling water installations in the streets and advised people to stay indoors. Dozens of Baltic Sea beaches have "no swimming" warnings due to health risks from algae blooms.

As farmers across the continent battle the effects of drought, the European Union has offered to speed up funds to help them cope.

At least eight of the EU's 28 member countries have also appealed for flexibility in the application of Europe's crop diversification and environment rules due to adverse weather.