Resumo: Over the last few decades, tourism has become increasingly important in the Spanish economy. With 83.5 million tourists in 2019, 11.7% of the national GDP comes from the tourism sector. Climate is one of the main aspects taken into consideration by people when choosing a tourist destination. The Holiday Climate Index (HCI) is a bioclimatic indicator that takes into account different climate variables (temperature, precipitation, humidity, wind and cloudiness), in order to determine whether the climatic conditions are suitable for urban tourist activities. Using HCI:Urban, the evolution of climatic comfort levels for the Peninsula and Balearic Islands (PB) in summer (June, July and August) has been analysed for the mid (2041-2060) and end of the century (2081-2100) under the RCP 4.5 and 8.5 climate scenarios. Taking as a reference the period 1986-2005, the results indicate a considerable increase in climatic comfort especially at the end of the century in the northern and north-western regions of the country, where the values reach the 'excellent' rating (HCI 80-90). At the same time, the progressive loss of comfort as a result of climate change in southern regions such as Extremadura, Murcia, Andalusia and the Balearic Islands will lead to changes in the spatial-temporal distribution of tourist flows. Although its formulation can be improved, the data provided by the HCI:Urban can be useful in the development of urban planning instruments, facilitating decision-making by authorities within a new tourism context.
