heat

A study published in Science Advances has shown that areas affected by extreme wildfires – characterised by rapid spread and great difficulty in extinguishing them – have lower tree cover and reduced resilience compared to less intense fires, which may lead to long-term changes in vegetation. The team analysed 32.1 million hectares of coniferous forest in Canada and the western United States that were affected by fires between 2012 and 2023. Of this area, more than a third was burnt by extreme fires. In these cases, they observed that the faster the fire front advances, the greater the size and severity of the fire and the greater the distance from seed sources for the surviving trees, paving the way for long-term changes in vegetation.

Extreme heat is intensifying due to climate change – heat whose hourly fluctuations are not captured by traditional daily temperature indicators. Research published in Nature Climate Change has analysed global hourly data from 1981 to 2023, alongside climate projections through to the end of the 21st century. More than 80 per cent of the world’s land surface showed an increase in heat. Under a high-emissions scenario, the authors predict that, for the period 2070–2099, each hot day could include more than four hours of additional high temperatures compared with current levels (2001–2023). They also predict that non-hot days could see a further three hours of high temperatures, which would likely go undetected by daily measurements. Low- and middle-income countries are the hardest hit, bearing more than three-quarters of current and future heat exposure.

Western Europe experienced its hottest June–July on record, according to data from the Copernicus Climate Change Service (C3S). July saw the third and fourth heatwaves since May, marking an exceptional spell of extreme heat this summer. Across much of the region, the drought observed in May and June also persisted and intensified, with exceptionally low rainfall and soil moisture in France, Spain, parts of Germany and the United Kingdom. These hot and dry conditions in Western Europe led to the spread and intensification of last month’s extreme wildfires in countries such as Spain and France, according to the report.

In some areas of Spain and France, the intensity of weather conditions that favour wildfires — heat, drought and wind — increased by up to 50 per cent between 2016 and 2025, compared with the period between 1981 and 2010. This is one of the conclusions of a study carried out by a team including Spanish researchers, which analysed national records of forest fires in southern Europe – Spain, Portugal, France, Italy and Greece – alongside meteorological and climatic data from 1981 to 2025. The data, published in Scientific Reports, show that the number of days with conditions conducive to fires also increased in some areas of these countries. However, the annual number of fires over the last decade was 40 per cent lower than in the 1981–2010 period in all countries – a decline which, according to the authors, is consistent with a reduction in fires caused by humans, driven by stricter regulations.

Early this morning, the Minister of Interior, Fernando Grande-Marlaska, declared a state of emergency of national interest in the Community of Madrid and the province of Ávila due to the forest fires in Villa del Prado, San Martín de Valdeiglesias and Burgohondo. According to Carlos Novillo, the Regional Minister for the Environment, Agriculture and the Interior of the Community of Madrid, the fires were beyond the capacity of the fire services to extinguish and posed a serious threat to the population. The Madrid 112 Security and Emergency Agency has reported that, although the night-time firefighting efforts have been effective, the fires have still not been contained or brought under control. More than 10,000 people remain evacuated.

Data from the Copernicus European Forest Fire Information System (EFFIS) show that, as of 22 July, 119,458 hectares have been burnt in Spain. The average number of hectares burnt from 2006 to 2025 up to this date stands at 35,736 hectares. The fire in the Sierra Norte de Guadalajara, which has scorched more than 30,000 hectares and is still active, together with numerous fire fronts in other provinces and the fire in Los Gallardos (Almería), in which 13 people died, have caused the total area burnt to soar.

Various studies show that extreme heat is already influencing the decisions of international tourists, who are cutting short their summer holidays in the Mediterranean and opting for coolcations in search of destinations with milder climates. Climate adaptation is becoming a priority and, in the face of increasingly intense heatwaves, may boost the appeal of spring and early autumn.

Air conditioning in buildings is necessary to combat the high temperatures of summers, which are becoming increasingly long and hot; however, it is not without controversy due to its energy consumption and environmental impact. Today, the WHO is presenting its new guidance on health and heat action plans, in which it acknowledges that air conditioning is problematic, while also emphasizing the need for vulnerable populations to have access to these systems. In a recent briefing organized by SMC Spain, we analyzed its role in the fight against global warming.

An analysis by World Weather Attribution shows that players and fans face a much higher risk of extreme heat and humidity at the 2026 FIFA World Cup—to be held from June 11 to July 19 in North America—compared to the 1994 tournament held on the same continent. The report analyzes the likelihood that each of the 104 matches to be played in Canada, the United States, and Mexico will meet the safety guidelines set by the FIFPRO players’ union. Nearly a quarter of the matches will be played when conditions exceed a wet-bulb temperature of 26°C—an index that measures the body’s ability to cool itself—which requires cooling breaks. In addition, five matches will exceed the 28°C threshold for this indicator—equivalent to 38°C in dry heat—a limit set by FIFPRO for postponing matches.

European regions with the greatest economic inequalities face a higher risk of mortality from both cold and heat, while wealthier regions face a higher risk during heat waves and a lower risk from cold. These findings come from a study led by the Barcelona Institute for Global Health (ISGlobal) and published in Nature Health. According to the authors, the greater vulnerability to heat in regions with higher GDP could be due to a greater presence of heat islands and urbanization in those areas, while the lower risk from cold could be explained by better-insulated homes and lower energy poverty. The results are based on an analysis of a mortality database covering the years 2000 to 2019 and including the urban and rural populations of 32 European countries.