Seasonal and diurnal variability of a water body's effects on the urban microclimate in a coastal city in Italy

Investigating diurnal and seasonal variations in a multi-domain approach still needs to be exploited for people's wellbeing in urban coastal areas. This study, therefore, presents an innovative method to assess the effects of urban water bodies accounting for hyperlocal climate conditions, continuously mapped via mobile/wearable environmental monitoring. This was performed via wearable sensing during winter and summer, analyzing eight urban canyons with different morphologies and anthropogenic activities. The water body's effect was assessed by comparing air temperature along these canyons, while heat stress was evaluated through Physiological Equivalent Temperature (PET). In winter, the sea effect was not explicitly identified. Conversely, the cooling effect was evident in summer. Despite statistically significant correlations between air temperature and distance from the sea, no association between air temperature and sky view factor (SVF) was detected. Additionally, particulate matter (PM) concentration analysis did not allow identifying specific anthropogenic actions and cannot behave as an effective proxy. However, different temperature trends in winter and summer may represent a clear and cheap-to-detect outcome of the anthropogenic complexity in every urban canyon, which includes varied urban features and local overheating forcing. This highlights the importance of hyperlocal microclimate monitoring accounting for these strategic differences to be detected, during heat waves for instance.