The Basque Government publishes the first study on climate evolution in the Basque Country over the past 50 years

19/06/2025

The report indicates an increase in the frequency and duration of heatwaves, a rise in sea level of more than 20 cm over the last two centuries and an increase of 0.3 °C in the average temperature in the Basque Country each decade since 1970. 

In 2023, the average sea surface temperature along the coasts of the Basque Country was the warmest on record. 

The Basque Government, through the Ihobe public company, and in collaboration with the Basque Meteorological Agency, Euskalmet, has published the first report "Estado del Clima en Euskadi" ("State of the Climate in the Basque Country"), which conducts a detailed analysis of climate evolution in the territory from 1970 to 2023, the year with the latest available data. 

This has been possible thanks to Euskalmet’s records, whereby data has been collected with greater local precision over the past 30 years, compared to data provided by Copernicus, the European Union's Earth Observation Programme. 

The "State of the Climate in the Basque Country" synthesises international and regional scientific data, providing a comprehensive view of the changes in the climate observed in the territory to date, and complements the analyses of future climate projections, providing more accurate data adapted to the local reality. In particular, the report highlights a continued rise in temperatures, more frequent extreme events, such as heatwaves and rising sea levels, underlining the urgency of implementing climate change mitigation and adaptation measures. 

The data speaks volumes. The planet is unequivocally warming: 2024 was the warmest year on record and the first full year to exceed an increase of 1.5 °C above the temperature registered in the pre-industrial era. Furthermore, Europe is still the world’s fastest warming region, with a temperature increase of around 2.4 °C since the pre-industrial era, which is almost one degree higher than the global average. 

"The Basque Country is no stranger to this. According to the climate change scenarios developed by Ihobe, the temperature could increase by up to 5 ºC by the end of the century, producing impacts derived not only from the heat, which will affect citizens, infrastructures and businesses and will increase the risk of droughts and fires, but also from changes in the length of the seasons and in the rainfall, which will affect agriculture and the natural environment", pointed out the Basque Government's Deputy Minister for the Environment, Josu Bilbao. 

The Basque Country has a specific climate marked by the influence of the Bay of Biscay, its proximity to the Pyrenees, as well as the existence of two climatic zones (Atlantic and Mediterranean) and a transition zone. For this reason, the Basque Government’s meteorological and climate monitoring through Euskalmet is of particular importance, as well as the early warning systems on which it is based, such as river, oceanic and meteorological measurement systems; modelling and prediction systems; and warning systems for emergency services, administrations and the population. 

Key data from the report 

Since 1970, the temperature in the Basque Country has increased by 0.3 °C each decade. 2022 and 2023 were the warmest years on record. The report highlights an increase in the frequency and duration of heatwaves. Hot and very hot days, on which average and maximum temperatures are abnormally high, as well as hot nights, with abnormally high minimum temperatures, have increased by six days each decade since 1970. Summer days, i.e. days when the maximum temperature exceeds 25 °C, have increased by four days each decade. 2022 and 2023 stand out for having had more than 75 hot days, exceeding those recorded in 2020, the third warmest year, by more than 20 days. 

The number of heatwave days has doubled from 4 days in the 1970-2000 period to almost 9 in the 2014-2023 period. The average maximum temperature recorded during hot spells has also increased. Although the longest event was recorded in 2003, lasting between twelve and thirteen days, 2022 saw the highest number of heatwave days, becoming an unprecedented year with more than twenty-three heatwave days. This data is accompanied by a decrease in the number of cold and frosty days. 

Sea levels have risen by 2.5 mm each year since 1993. The Brest tide gauge, i.e. the instrument that records seawater levels over time, which is located in this French city in the Bay of Biscay, has recorded a rise of more than 20 cm over the last two centuries, with a more pronounced increase in the 21st century. 

Sea levels are projected to rise by 26 cm by 2050 and by 51-100 cm by 2100. This is a major threat bearing in mind that approximately 60% of the Basque population lives in coastal municipalities and it is estimated that by 2100, up to 40,000 people could be living in a flood zone in the worst case scenario. 

As for the sea surface temperature in the Bay of Biscay, it has increased by around 0.25 °C each decade. In 2023, anomalies exceeded the 1 °C threshold with respect to the 1991-2020 period. In 2023, the average sea surface temperature along the Basque coasts was the warmest ever recorded to date. 

With regard to rainfall in the Basque Country, the report does not show any clear trends, but points out that 1989 was the driest year and 2013 was the wettest. Furthermore, no significant changes in the frequency of extreme precipitation events have been observed. 

As for global warming gases, the report recalls that greenhouse gas emissions in the Basque Country have fallen by 33% since 2005, in line with the objectives of the Basque Country's Energy Transition and Climate Change Plan. However, it points out that the transport sector has seen an increase of 135% in emissions since 1990. 

Climate action to mitigate warming and adapt the territory 

The "State of the Climate in the Basque Country" report highlights the need to continue and strengthen the implementation of adaptation and mitigation measures to face climate challenges, as well as collaboration between institutions, companies and citizens to achieve a more resilient and sustainable future. 

Recent studies estimate that, according to information from reinsurance companies, total economic losses from weather and climate events between 1980 and 2021 amounted to more than €560 billion (in 2021 values) in the 27 EU Member States. According to this data, between only a third and a quarter of these losses were insured. In a +3°C scenario by the end of the century, the economic impact on the EU is expected to be €175 billion each year (1.4% of the EU GDP), while the figure would be halved if the temperature increase were slowed to below 2 °C. 

"In light of this data, it is important to adapt and minimise the impact of climate change. In the Basque Country, we have the Basque Law on Energy Transition and Climate Change, a pioneering law on climate change adaptation so much so that it is one of the few laws that currently places adaptation on the same level as mitigation, and which includes specific measures to make the Basque Country a resilient territory adapted to the worst effects of climate change", stressed the Deputy Minister, Josu Bilbao. 

To make the Basque Country more resilient to climate change, inter-institutional collaboration is needed to create new climate governance systems. This is precisely the aim of the KAIA (Klima Aldaketaren InpaktuA) coordination table, which has been presented recently and is led by the Basque Government's Directorate for Natural Heritage and Adaptation to Climate Change, in which the Basque Water Agency-URA, the Directorate for Territorial Planning and Urban Agenda, the Directorate for Emergency Attention and Meteorology and Azti participate in addition to Ihobe and Euskalmet. KAIA is already working on the deployment of 5 climate change adaptation demonstration projects: on the Zarautz waterfront, in the Bakio marshland, in the Astegieta meander in Vitoria-Gasteiz, in the Bilbao estuary and the in bay of Txingudi.