Widespread flooding, extreme heat and drought in eastern Europe
Widespread flooding in 2024
C3S
Spotlight topics for the ESOTC 2024 include an overview of flooding in Europe, with a focus on the extreme events in central and eastern Europe associated with Storm Boris, and those in Valencia, Spain, as well as the extreme heat and drought in southeastern Europe during the summer.
30% of the European river network exceeded the ‘high’ flood threshold during the year, while 12% exceeded the ‘severe’ flood threshold. In September, Storm Boris affected hundreds of thousands of people, with flooding, fatalities and damage in parts of Germany, Poland, Austria, Hungary, Czechia, Slovakia, Romania andItaly.
At the end of October, Spain saw extreme precipitation and flooding leading to devastating impacts and fatalities in the province of Valencia and neighbouring regions.
Southeastern Europe experienced its longest heatwave on record in July 2024, lasting 13 consecutive days and affecting 55% of the region. There were recordbreaking numbers of days with at least ‘strong heat stress’ (66) and tropical nights (23) in southeastern Europe during summer.
For the first time, these spotlight sections also provide information on trends in flooding, and extreme heat and drought in Europe, summarising key findings from the Intergovernmental Panel on Climate Change (IPCC). For example, Europe is one of the regions with the largest projected increase in flood risk, and a global warming of 1.5ºC could result in 30,000 annual deaths in Europe due to extreme heat.
Climate policy and action
This year, the interactive map of key events also features a new layer highlighting examples of climate resilience and adaptation initiatives in cities across Europe.
Climate resilience and adaptation initiatives 2024
C3S
51% of European cities have adopted dedicated climate adaptation plans, representing encouraging progress from 26% in 2018, according to the climate policy and action section of the report, highlighting that continued efforts will unlock even greater potential to adapt to climate challenges effectively. Extreme weather events pose increasing risks to Europe’s built environment and infrastructure and the services they support.
Striking climate contrasts
In 2024, people living in different parts of Europe experienced very different weather and climate with a distinct east-west contrast of dry, sunny and extremely warm conditions in the east and cloudier, wetter and less warm conditions in the west.
(Left) Annual sunshine duration anomalies (%) for Europe for 1983–2024, showing positive (orange) and negative (grey) anomalies. (Right) Sunshine duration anomalies (hours) over Europe for 2024, showing positive (shades of orange) and negative (shades of grey) anomalies. Reference period: 1991– 2020. Data: CM SAF SARAH-3 CDR and ICDR.
C3S/ECMWF/DWD/EUMETSAT
This east-west contrast was apparent in many climate variables, such as temperature, precipitation, soil moisture, clouds, sunshine duration, solar radiation and potential for solar power generation. Consequently, the contrast was also reflected in terms of the European river network, with widespread higher-than-average river flows in western Europe and lower-than-average flows in eastern Europe.
Anomalies and extremes in annual average river flow in 2024. Reference: extremes 1992-2024, anomalies 1992– 2020. Data: EFAS.
CEMS/C3S/ECMWF
Renewable energy progress
The proportion of electricity generation by renewables in Europe reached a record high in 2024, at 45%, compared to the previous record of 43% in 2023, reflecting Europe’s efforts towards a decarbonised energy system. The number of EU countries where renewables generate more electricity than fossil fuels has nearly doubled since 2019, rising from 12 to 20, according to reports.
Percentage of the total actual annual actual electricity generation for Europe, from solar (yellow), wind (purple) and hydro (blue) power, for 2016–2024. Data: ENTSO-E and Elexon.
C3S/ECMWF
Renewable power generation and electricity demand are highly sensitive to weather conditions, and the climate-driven potential for power generation from solar photovoltaic reflected the contrasting east (sunnier) and west (cloudier) conditions.
Increasing heat stress, day and night
Heat stress days and tropical nights are increasing in Europe – 2024 saw the second-highest number of heat stress days and tropical nights on record; averaged over Europe, this meant nearly a month of at least ‘strong heat stress’ and around 12 tropical nights, with variations across the continent and southeastern Europe in particular seeing record-breaking numbers of both. Heat can put the body under stress, influenced not only by temperature but also by other environmental factors such as wind and humidity. High nighttime temperatures can also affect health, offering little respite from daytime heat stress.
Annual average number of days with at least ‘strong’, ‘very strong’ or ‘extreme heat stress’ for Europe, from 1950–2024. The thresholds for ‘strong’, ‘very strong’ and ‘extreme heat stress’ are 32°C, 38°C and 46°C, respectively, based on the Universal Thermal Climate Index (UTCI). ‘Tropical nights’ are those during which the temperature does not fall below 20°C. Data: ERA5-HEAT, ERA5.
C3S/ECMWF
Shrinking glaciers
Melting glaciers 2024
The United Nations have declared 2025 as the International Year of Glaciers’ Preservation. ESOTC 2024 data show that glaciers in all European regions saw a loss of ice. Central Europe is one of the regions in the world where glaciers are shrinking the fastest, and the report includes a compelling infographic representing how much glaciers in the Alps have changed since the 1970s.
Glaciers in Scandinavia and Svalbard in 2024 experienced their highest rates of mass loss on record and saw the largest annual mass loss of all glacier regions globally, with an average thickness loss of 1.8 m in Scandinavia and 2.7 m in Svalbard. It was the third warmest year on record for the Arctic as a whole and the fourth warmest for Arctic land.
For the third summer in a row, the average temperature in Svalbard reached a new record high. In recent decades, this area has been one of the fastest-warming places on Earth.
