Earth and climate
Extreme heat in Europe 2026: record heatwaves, drought and deaths
Le estati europee stanno subendo una profonda trasformazione, con eventi meteorologici di extreme heat che si manifestano con frequenza e intensità crescenti.
In brief
Summer 2026 brought record-breaking heat, repeated heatwaves and severe drought across Europe, causing thousands of excess deaths, low river levels, energy and transport disruptions, and accelerated forest biomass loss, underscoring urgent needs for heat-health measures, water and forest management, and expanded cooling access.
Key points
- Prioritize heat-health action plans focusing on older and vulnerable populations.
- Increase cooling access and community cooling centers where home air conditioning is low.
- Protect and manage water resources to cope with low river levels and drought impacts.
- Accelerate forest resilience measures to reduce biomass loss and maintain carbon uptake.
- Integrate satellite monitoring into planning to detect and respond quickly to heat, drought and ecosystem stress.
Le estati europee stanno subendo una profonda trasformazione, con eventi meteorologici di extreme heat che si manifestano con frequenza e intensità crescenti. The summer of 2026 provided a clear example of this new normal. It was marked by prolonged heatwaves and widespread drought that strained infrastructure and public health. As early as May of that year, western Europe felt an early preview of an unusual summer, when a heat dome, a mass of warm, stable air that traps heat at the surface, produced exceptional temperatures that broke every record.
By mid-August 2026, Europeans were facing the fifth heatwave of the season. The latest surge pushed temperatures well above 40 degrees Celsius across a wide area. These high temperatures were often relentless, persisting for days and sometimes weeks, and remaining elevated even at night. The combined temperatures of June and July 2026 are the highest ever recorded.
The Human Toll of Extreme Heat Waves
These extreme heat waves did not only cause widespread discomfort but also a significant rise in heat exhaustion and heatstroke. Preliminary reports suggest that the heat may have been associated with around 10,000 excess deaths. About 10,000 excess deaths are associated with the heat. Data indicate the phenomenon hit the United Kingdom, France, Germany and Belgium particularly hard, with thousands more deaths than average.
European vulnerabilities include low air conditioning penetration, present in only 23% of homes. Only 23% of homes have air conditioning. This figure is markedly below the 90% in the United States and contributes to higher death rates in European cities during heatwaves compared with comparable American cities. Nighttime heat is particularly harmful for older people whose homes lack air conditioning.
For older adults with preexisting physical health conditions, temperatures as low as 26.7°C can pose a significant danger. The World Health Organization states that heat stress is the leading cause of weather-related deaths worldwide, exacerbating existing conditions. Heat stress is the leading cause of weather-related deaths. Researchers have estimated about 489,000 heat-related deaths each year, with 36% of these in Europe.
Deborah Carr, a sociologist at Boston University, used demographic and NASA climate data to identify areas at greatest risk of heat exposure. Her research found southern Europe among the most exposed areas, with an aging population and therefore greater vulnerability. A study published in Lancet Planetary Health in August 2026, led by Qinqin Kong, mapped where rising heat will lead to intolerable conditions in coming decades.
The research concluded that safety thresholds will often be exceeded at large scales. The risks will fall disproportionately on older people. Dr Kong explained that the human body tolerates only a limited range of environmental heat, and that understanding where and when these limits are surpassed is essential to inform action plans and health planning.
About 10,000 excess deaths are associated with the heat.
Rivers Running Dry and the European Water Crisis
The scorching temperatures of 2026 worsened the severe drought that had plagued the region for months. This phenomenon caused record-low river levels and disruptions to water and energy supplies. It also created problems for transport routes and agriculture. Copernicus Sentinel-2 satellite images showed a stretch of the Danube in Hungary, about 45 km north of Budapest, much lower than the previous year.
On 4 August 2026 the river appeared noticeably lower, with sandbanks visible compared with 9 August 2025. This record-low condition of the Danube had direct consequences. Energy and water shortages were reported near Budapest. Barges and river ferries encountered operational problems.
The record levels of the Danube are not an isolated 2026 phenomenon but reflect recurring events related to drought and heatwaves. Minimum water levels have been recorded in the river since 2018. The impact extends to wildlife, with fish struggling to survive due to higher water temperatures. Pollutant concentration and falling oxygen levels worsen the situation.
The Danube, the longest river in the European Union, also recorded low levels in Romania. These hydrological changes threaten agriculture, freshwater ecosystems and river transport across multiple countries. Policy responses will need to consider both short-term relief and long-term adaptation.
Europe’s Forests: A Green Lung Under Attack
Drought, exacerbated by extreme heat waves, is putting Europe’s forests at risk. These cover about 39% of the continent’s land area. Forests store 10.6 billion tonnes of carbon in above-ground biomass, one of the largest terrestrial carbon stocks in Europe. A study published in Nature Geoscience revealed that European forests are losing more biomass than previously thought.
European forests are losing more biomass. Losses have risen sharply since 2018. For the first time, scientists quantified how much biomass is lost due to forest disturbances across Europe. They measured biomass loss rather than just the affected area.
They found that for every hectare of disturbed forest, biomass loss has increased by 46% since 2018. Causes of this accelerated loss include drought, windstorms and insect outbreaks, such as the bark beetle. The bark beetle can kill a mature tree within weeks, especially after severe droughts.
Between 1985 and 2023, logging accounted for about 82% of biomass loss, while the remaining 18% from natural disturbances drove the sharp increase since 2018. These disturbances exceed forests’ ability to regrow and recover naturally. The result is a long-term reduction in carbon storage potential and ecosystem services.
A second study, published in National Science Review and supported by the ESA’s RECCAP-2 project, projected a reduction in European forests’ carbon uptake capacity for the 2010-2030 period. Carbon uptake capacity will decline by 39% over 2010-2030. The RECCAP-2 project uses satellite data to support the Paris Agreement’s Global Stocktake.
Philippe Ciais, co-author of the study, noted that Europe can expand its forest area yet still lose carbon uptake capacity if growth and recovery do not keep pace with disturbances and harvest. This interconnected scenario of heatwaves, drought and ecosystem degradation requires urgent rethinking of environmental management strategies.
Safety thresholds of the human body will often be exceeded at large scales. This will create health risks concentrated among the most vulnerable people.
The interaction between heatwaves, drought and forest disturbances can drastically reduce the recovery capacity of natural systems. This demands targeted environmental management interventions.
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