Countries such as France, Spain and parts of Italy are marked in red on the map at the EU's weather service Copernicus. The dark red color means that the temperature for 2025 is the warmest measured since 1979 for the period between June 17 and July 2.
Already at the end of May, a huge heat wave came over the Iberian Peninsula, which led to high temperatures in both Portugal and Spain, says Gunilla Svensson, professor of meteorology.
The fact that the heat waves came at the turn of the month to June is unusual, according to several researchers. Spain was one of the countries that was affected, and continues to be affected, by extreme heat. This summer, a new heat record was set for June, when the village of El Granado in Andalusia measured 46 degrees.
Even longer European summer
Going forward, heat waves are expected to strike both before and after Europe's traditional summer months, as climate change makes the Earth warmer.
The trend is that heat waves will become more frequent, affect larger areas and become more intense, says Markku Rummukainen, professor of climatology at Lund University.
Gabriele Messori, professor of meteorology at Uppsala University, emphasizes the same thing.
You will get a longer European summer, he says.
The heat has continued to ravage both July and August. This week, there have been reports of deaths due to the heat, further heat records and what is described as "hell fires" in and outside Europe.
When the parents of today's children were small, it was not common with such early extreme heat waves, says Gabriele Messori about the development.
"Extremely hot for the season"
In Sweden, a heat wave is defined as a continuous period of five days, when the highest temperature per day is at least 25 degrees.
Some may think it's nice and others don't, but regardless, society, ecosystems and agriculture are not adapted to long dry hot summer periods in many ways, says Gabriele Messori.
Can heat waves ravage all year round in the end?
There is no physical limit to how early heat waves can come. If it's 25 degrees warm in January in southern Europe, most people wouldn't call it a heat wave, but it's still extremely hot for the season, adds the Uppsala researcher.
The definition of a heat wave varies from country to country and climate. It refers to conditions that are significantly warmer than what is usual for the region.
In Sweden, there are several variants, but according to one definition, it is "a continuous period when the highest temperature per day is at least 25 degrees for at least five days in a row".
As a result of today's climate change, heat waves occur earlier and earlier. This year, a severe heat wave struck already in May in Europe.
Research shows that they can be expected to become longer, more intense and more frequent in the future. The increase is due to human impact on the climate.
Source: SMHI, Stockholm University, Lund University.
