Climate projections of intensifying heat waves in the Canary Islands by 2100 (Spain)

Abstract Heat waves, episodes of abnormally high temperatures sustained for several days, have increased in frequency, duration and intensity in recent decades as a consequence of climate change. This study analyses their evolution in the Canary Islands using historical data (1981–2010) and regionalised climate projections up to 2100, using the FICLIMA method and CMIP6 ensemble models. Four key indicators were evaluated: frequency, mean duration, mean intensity and maximum intensity of these events. The results indicate a substantial increase in heat waves across all islands, with a more pronounced increase observed in eastern islands such as Fuerteventura, where up to 6.5 additional episodes per year could be recorded under the most adverse scenarios. Furthermore, an increase in the average duration is anticipated, with this reaching up to 10 consecutive days and more than 60 days per year under extreme conditions on certain islands. While the mean temperature during these events is expected to rise, the maximum intensity is projected to rise more substantially, particularly in the western islands. These changes pose a major challenge for future climate adaptation in the region, with direct implications for public health, water resource management and key sectors such as tourism and agriculture. The results provide scientific evidence for the design of mitigation and adaptation strategies aimed at reducing the impacts of these extreme events on the population and ecosystems of the archipelago.