Microclimatic Variability and Thermal Discomfort during a Terral Event: The Role of Vegetation and Urban Form in Málaga, Spain

Extreme heat events pose significant challenges for Mediterranean cities. This study evaluates the influence of vegetation and urban morphology on thermal comfort during an extreme heat episode in Málaga (Spain). Air temperature, relative humidity, land-surface temperature (LST), and the Temperature–Humidity Index (THI) were assessed across 13 green and grey infrastructures.

Microclimatic measurements were conducted in situ during a terral event in August 2024, a local hot-and-dry wind phenomenon. Air temperature and relative humidity were recorded every two hours using a thermo-hygrometer, while surface temperature was assessed every four hours using infrared thermography. A Bayesian linear modeling framework was applied to estimate posterior means and credibility intervals to evaluate spatial and temporal variability.

The results revealed marked thermal heterogeneity. Sites with continuous tree canopy or shading structures exhibited lower air and surface temperatures and more favorable THI values than exposed impervious surfaces. In contrast, children’s playgrounds, bus shelters, and sports facilities reached critical surface temperatures and experienced elevated thermal discomfort for prolonged periods. Narrow streets exhibited relatively favorable thermal conditions due to self-shading, even in the absence of tree cover, indicating a complementary effect of urban morphology.

These findings underscore the importance of integrating vegetation and urban form into climate-adaptive planning strategies. The study provides empirical evidence supporting the prioritization of thermally vulnerable urban typologies. It reinforces the role of green infrastructure and passive design strategies in enhancing the thermal resilience of Mediterranean cities.