As extreme heat grips much of Europe, soaring temperatures across Spain and Portugal have forced authorities to declare states of emergency, prompting wildfire warnings and forest closures.

A mass of hot air from North Africa has brought temperatures of 36-44 C to the Iberian Peninsula.

Portugal's Interior Minister Maria Lucia Amaral announced restrictions on access and movement within forest areas, in line with forest fire defense plans, reported Euronews on Monday. Fireworks, machinery operations and burning activities must be banned as the nation tackles the extreme temperatures, she said.

The minister said the preventive measures would be implemented in response to the combination of high heat, low humidity and elevated wildfire risks.

Red alerts have been issued for five northern districts of the country until Tuesday, with the rest of Portugal at the orange level except for the district of Faro, which remains at yellow. The overall high alert situation is expected to remain in place until Thursday.

Forest fires continued to rage across northern Portugal on Sunday, forcing the evacuation of at least one village in the Douro region.

Spain is experiencing its second summer heat wave, which is forecast to persist until the end of the week. Forecasts from the Spanish state meteorological agency Aemet indicate the extreme conditions will affect most of Spain, excluding the Cantabrian region and the Canary Islands.

Spain's Health Ministry has issued "red risk" health alerts across hundreds of municipalities.

Nordic nations are experiencing "truly unprecedented" heat, as temperatures strengthened and prolonged by carbon pollution continue to sweep across northern Europe, reported The Guardian newspaper.

A weather station in Norway's Arctic Circle recorded temperatures above 30 C for 13 days in July, while Finland has experienced three consecutive weeks of 30 C heat. According to scientists, the area has endured its longest period of sustained heat since the 1960s.