Are activities areas (LCZ8) really warmer than other parts of the city? Case study in an old European city

Abstract

“Large Low Rise” Local Climate Zone 8 (LCZ 8) offers many urban variations from one country to another. Despite a marked presence in the spatial organization of our urban territories, and evidence of high occurrence of high surface temperature through satellite images, their local micro-climate in terms of air temperature is not yet explored in climatology studies. In Toulouse, among the weather stations in the large measurement network deployed in recent years on the whole agglomeration, 8 LCZ8 “activity area” covering office, retail and industrial areas are monitored. They are compared to other LCZs, and their intra-LCZ8 summertime air temperature variability is explored, in relation with the local winds. This study demonstrates that LCZ8 activity areas are not, even during daytime, warmer than other urban zones in terms of air temperature, and even cooler than LCZ3 and LCZ2, contrary to what surface temperature observations might suggest. Results also emphasize the need for nuanced, site-specific approaches to urban heat management and underscore the value of dense, high-quality meteorological networks in informing evidence-based climate adaptation policies.