Why wildfires in Europe are so intense this year
Heavy rains followed by an extreme heat wave created the perfect conditions for the spread of fire.
Some of the largest wildfires to hit Europe since World War II began following an unusual factor: an especially rainy winter. It accelerated the growth of vegetation, which then dried out after one of the driest and most extreme heat waves on record.
The result was a vast area of dry vegetation that became fuel for burning.
In recent days, all it took was a spark to ignite it, and massive wildfires spread across large areas in France and Spain, forcing more than 300,000 people to evacuate their homes.
"The worst natural disaster in Spain's history"
In the southwest of France, near Bordeaux, more than 405,000 hectares have burned. The fire spread rapidly through the region’s vast pine forests, forcing more than 220,000 residents and vacationers to evacuate in the middle of the tourist season.
In Spain, wildfires have destroyed more than 1.5 million hectares since the start of the year. Isabel Díaz Ayuso, president of the Community of Madrid, stated earlier this week that this may be "the worst natural disaster in Spain's history."
The intensity of the wildfires led, for the first time in France’s modern history, to the formation of fire-fueled thunderstorms, known as pyrocumulonimbus clouds. These clouds, previously recorded during major wildfires in Canada and Australia, form when intense heat lifts hot smoke into the air and causes water vapor to condense around ash particles. The clouds can create lightning, thereby contributing to the spread of wildfires.
According to scientists, the rise in temperatures in Europe has prepared the ground for extreme weather conditions. Europe is the continent warming at the fastest rate in the world. Temperatures in Europe are already 2.5 degrees Celsius higher than in the pre-industrial period, while the global average increase is only 1.4 degrees.
"These are two sides of the same coin," said Francesca Di Giuseppe, a wildfire forecast coordinator for medium-range weather forecasting in Central Europe. "We are moving from an extremely wet period to an extremely dry one."
"The hottest summer in meteorological history"
In recent months, several heat waves have struck Europe. June was particularly difficult, with temperatures exceeding 40 degrees Celsius in some areas—the hottest June ever recorded in Western Europe.
"All signs point to the fact that summer 2026 will be the hottest in the recorded meteorological history of Spain and France," said Javier Martín Vida, a climate expert and professor at the University of Barcelona.
Warm air can hold more water vapor, which dries out vegetation. Rising temperatures also extend the wildfire season in Europe, and officials say the current season may last until early November.
Another factor behind the increasing intensity of wildfires is the growth of natural vegetation. Many young people have left rural areas for jobs in cities, leaving behind agricultural lands that previously served as effective firebreaks. Fields and forests remain unmanaged, and shrubs spread in areas where animals used to graze.
In parts of Europe, including Catalonia in northeastern Spain, forest cover today is among the highest recorded in the last 100,000 years, according to estimates by Víctor Resco de Dios, a forestry expert at the University of Lleida.
"An enormous amount of combustible material"
"In our forests, an enormous amount of combustible material has accumulated, which is why the wildfires are so intense. This fuel is not the trees themselves, but mainly what is underneath them, such as scrub, shrubs, and the layer of dry leaves on the ground," Resco de Dios said.
Active wildfires in the Madrid area began last week with about three separate fires that spread out of control and ultimately merged into one large blaze. According to Resco de Dios, the fires threatening Madrid released energy equivalent to about 29 atomic bombs dropped on Hiroshima.
Firefighting teams have made some progress in containing the fire, allowing several thousand people to return home on Tuesday. However, Spanish authorities warned that another heat wave and strong winds expected this week could make containment efforts more difficult.
"We are managing to reverse the trend and we are starting to see the light at the end of the tunnel in the fight against these wildfires," Spanish Prime Minister Pedro Sánchez said on Tuesday. However, he warned that "we have complex days and hours ahead of us."
