As Europe bakes in its first major heatwave of the year, temperature records are being broken across the continent.
During June, countries experienced temperatures more typical of July and August, with records broken from the Arctic Circle to the Mediterranean.
The Portuguese weather service (IPMA) reported 46.6 °C in Mora on 29 June - the hottest ever recorded in mainland Portugal during June. Norway’s Banak station reached 32.5°C, the highest temperature ever recorded within the European Arctic for the month.
The extreme heat has brought health warnings, school closures and restrictions on outdoor work.
The European Centre for Medium-Range Weather Forecasts (ECMWF) has said that for the continent as a whole, this month is likely to rank among the top five warmest Junes on record.
How long will Europe’s heatwave last?
Scientists have said that this extended period of above-average temperatures is being caused by a heat dome. This is when a high-pressure area stays over the same place for days or even weeks, trapping the hot air below it. This acts something like a saucepan lid, causing temperatures to become hotter and hotter.
Last week, a strong area of high pressure built over Western Europe. It extended up across Spain and Portugal into France, then spread to Germany and Italy over the weekend.
After days of record-breaking heat, forecasters say there will be some relief on Wednesday into Thursday as thunderstorms and cooler temperatures arrive from the Atlantic, according to Météo-France. Spain and Italy may have to wait until the weekend to see temperatures begin to drop.
France sees its second-hottest June since 1900
In France, temperatures of 40°C were recorded in Paris on Tuesday. The country's national weather agency placed several regions under the highest red alert.
More than 1,300 schools were fully or partially closed across the country, and the summit of the Eiffel Tower has been closed to visitors until Thursday because of the heat.
"June 2025 has become the second hottest June since records began in 1900, behind June 2003," French Ecology Minister Agnes Pannier-Runacher said on Wednesday morning.
30 June was the hottest day since measurements began in 1947, according to Météo-France.
Later, Pannier-Runacher added that more than 300 people have been taken into emergency care, and two had died as a result of heat-related illnesses.
June ‘pulverised’ heat records in Spain
Spanish weather service Aemet said that an “extremely hot” June had “pulverised records”, surpassing the normal averages for July and August.
It recorded an average of 23.6°C - the highest for the month in 64 years and 0.8°C higher than the previous record set in 2017. Provisional data shows that nine days in June broke records for their respective dates. Aemet says that in an “undisturbed climate”, five record warm days would be expected in an entire year.
Ramón Pascual, a delegate for Spain’s weather service in Barcelona, told The Associated Press the "very intense heat wave” is clearly linked to global warming.
High sea surface temperatures in the Mediterranean are not helping either, as they reduce any cooling effects a nearby body of water might have.
Millions of Europeans are being exposed to high heat stress
The June-July heatwave is exposing millions of Europeans to high heat stress, according to Samantha Burgess, strategic lead for climate at the ECMWF.
“And our reanalysis data shows that many Europeans have experienced very high temperatures for the period since the start of June,” she adds.
“The temperatures observed recently are more typical of the months of July and August and tend to only happen a few times each summer. We saw it again in 2024, the warmest year on record.”
Burgess also says climate change is making heatwaves more frequent and more intense, and they are now impacting larger geographical areas.
Hot spells like this could become more frequent in the UK
The UK experienced its hottest day of the year so far on Tuesday with a recorded temperature of 34.7°C in London’s St James’s Park.
Provisional data from the Met Office indicates that the country experienced its second warmest June since 1884. The average temperature for the month reached 15.2°C, only surpassed by June 2023, which saw average temperatures of 15.8°C.
It follows a record-breaking spring that was officially the warmest and sunniest on record.
June continued that trend, the Met Office said, marked by two heatwaves and high temperatures at the end of the month.
“While we’ve not conducted formal climate attribution studies into June 2025’s two heatwaves, past studies have shown it is virtually certain that human influence has increased the occurrence and intensity of extreme heat events such as this,” says Met Office climate scientist Dr Amy Doherty.
Doherty adds that numerous climate attribution studies have shown that human influence increased the chance of specific heatwaves occurring, including those in summer 2018 and July 2022.
"Our Met Office climate projections indicate that hot spells will become more frequent in our future climate, particularly over the southeast of the UK. Temperatures are projected to rise in all seasons, but the heat would be most intense in summer."
