Thermal comfort and the role of coastal breezes during heatwaves in the southwestern Iberian Peninsula: insights from observations and WRF modeling.

In the last years, the frequency and impacts of heatwaves have risen significantly, with Spain experiencing a near doubling of these extreme events (Núñez Mora, 2021). In littoral regions, coastal breezes—driven by temperature gradients between land and sea surfaces—can play a crucial role in mitigating extreme temperatures.  This study focuses on the influence of coastal breezes in the southwest of the Iberian Peninsula on thermal comfort during a heatwave period.

Coastal areas have experienced significant urban development, as approximately 60% of the Spanish population lives in these regions (de Andrés et al., 2017). In these terms, urban heat exposure is shaped by meteorological variables that operate across multiple spatial and temporal scales. For instance, in the city, temperature and humidity exhibit variations on scales of hundreds of meters, while the heterogeneity of the wind speed and shortwave/longwave radiation are highly localized, influenced by individual buildings and fluctuating over just a few meters.  

To assess the impact of coastal breezes on thermal comfort, we analyze observational data from meteorological stations and model output from the Weather Research and Forecasting (WRF) model, incorporating the urban parameterization WRF-Comfort (Martilli et al., 2024). This approach enables us to evaluate the thermoregulatory effects of breezes and compare simulated results against observational data, offering insights into mesoscale interactions between urban dynamics and regional climate processes during extreme heat events.  This research highlights the importance of integrating mesoscale modeling with urban processes to better understand climate extremes and their mitigation. Given the strong link between thermal comfort and human well-being, understanding these interactions is essential for developing strategies to reduce heat-related health risks in urban populations.