The last heat wave leaves 286 people who died in Barcelona, 108 fatalities in Madrid and 2,300 in the main cities of Europe. That means that the two most populated cities in Spain add up to total, almost 400 deaths from high temperatureswhich represents 17% of the total estimated in the continent.
This is concluded by a study by the International Scientific Group World Weather Attribution (WWA), which calculates that the 65% of extreme heat deaths happened in 12 major European cities between June 23 and July 2, 2025 were caused directly by climate change And, therefore, they could have avoided whether the burning of fossil fuels would not have exacerbated global warming.
The report, led by researchers from the Imperial College in London and the London Tropical Hygiene and Medicine School, points out that high temperatures caused some 2,300 deaths in cities such as Madrid, Barcelona, Paris, Rome, Lisbon or Athens. Of these, 1,500 deaths are attributed to the climatic crisis, which for them shows the direct impact of global warming on public health.
“This study shows why heat waves They are known as silent murderers, “said Malcolm Mistry, an deputy professor at the London Tropical Hygiene and Medicine They will register as related to heat, “he says.
Madrid spent more heat, but in Barcelona there were more deaths
In Spain, the contrast between Madrid and Barcelona is especially striking. According to the study data, 340 people died during the heat wave that ended in early July, of which 286 deaths are linked to climate change. In Madrid, 118 deaths were recorded, 108 attributable to global warming. The surprising thing is that the average temperature was higher in Madrid (30.16 ºC) that in Barcelona (29.04 ºC), which led researchers to analyze possible structural differences between both cities.
“There is evidence that people in Barcelona, for reasons that we have not taken into account in the study, is more vulnerable,” said one of the authors of the report during a press conference in Brussels. “It may be for the proportion of Most vulnerable unipersonal housingFor example”.
On the other hand, despite registering fewer deaths, Madrid experiences a more intense increase in temperatures during heat waves. In the latter, the Spanish capital supported a thermal increase of +3.68 ºC with respect to the usual values, the highest among the 12 cities analyzed.
“Madrid is practically in the center of Spain and is not very coastal, something that does not happen in Lisbon, for example,” said one of the researchers. And he added that “the ocean is heated more slowly than the earth, and that explains why the increase in Madrid is more aggressive.” Lisbon, in comparison, experienced an increase of just 1.13 ºC during the same period.
The profile of the victims: over 65 years
The report warns that climate change hits the most vulnerable people with special hardness. 88% of the deaths attributable to global warming were people over 65 years old. This “highlights that people with underlying medical conditions are the highest risk of premature death during heat waves,” the study underlines.
Extreme climatic conditions, increasingly frequent and intense, are becoming a Direct threat to public health In Europe, especially for those who already suffer chronic pathologies. In addition, it has been proven that heat accelerates aging and can advance risk or premature pregnancies.
Europe, at the point of heat
The heat wave at the end of June and early July forced emergency measures in several countries. In France, schools were closed; In Italy, it was forbidden to work outdoors in the hottest hours, in Crete there were evacuations for a great fire and Serbia reached its highest temperature since the 19th century. The study results place the focus on the need to adapt European cities to the new climatic context, according to the authors.
In addition, they indicate that the differences between regions show that, although temperatures are similar, the vulnerability that entails is not. Therefore, WWA scientists urge European governments to reinforce their emergency plansadapt urban infrastructure and protect the most vulnerable populations before the next heat wave will take lives again. “This report is not just a scientific estimate. It is an alert,” they conclude.