Spain sweated under its first official heatwave of the year, with temperatures expected to reach 40C in a large swathe of the country on Thursday, while Italy, Greece and other areas of southern Europe also struggled to stay cool.

After a relatively bearable spring compared with record heat in 2023 and 2022, millions of Spaniards will be sweltering at least until Saturday before feeling any relief.

The country’s weather authority said the only areas to be spared will be the northwest and northern Atlantic coasts.

Weather forecasters said a mass of hot air travelling across the Mediterranean from northern Africa will settle over central and southern Spain.

That, combined with the typical harsh summer sun, will make cities like the medieval cites of Seville, Toledo and Granada bake.

The hottest area will be the southern Guadalquivir River basin where the temperature could reach 44C. Six regions are under alerts for high temperatures.

The hottest year for Spain since it started keeping records in 1961 was 2022; 2023 came in as the second hottest year. The first heatwave for last year arrived in June.

Authorities and experts agree that climate change is behind the rise in temperatures that is also feeding prolonged droughts and wildfires in the Mediterranean and other parts of the world.

In Spain, a heatwave is a minimum of three consecutive days during which at least 10% of weather stations register highs above the 95% percentile of average maximum temperatures for July and August.

Hot, dry winds scorched Greece, where a prolonged heatwave was at its peak on Wednesday and Thursday.

Temperatures touched 43C in several parts of the country, while night-time temperatures in parts of Athens remained above 30C for the past 10 days.

Firefighters were fighting two large blazes on Thursday, one near a village on the outskirts of the northern city of Thessaloniki, and a brush fire on the island of Kea, near Athens.

Emergency services ordered the evacuation of two areas on Kea, while local media said the fire near Thessaloniki had damaged several homes.

“We appeal to the public to be particularly careful as over the next few days there is a very high risk of the outbreak of serious wildfires,” government spokesman Pavlos Marinakis said.

“Even one spark can cause a major catastrophe.”

Italy put 14 cities put under the highest level of alert and temperatures are expected to climb above 40C, especially in the central and southern regions.

The health ministry said it will further extend the red alert to 17 Italian cities on Friday, as the intense heat was forecast to continue until Sunday.

On Tuesday, Serbia’s state power company reported record consumption due to the use of air conditioning.