The application of a high-density street-level air temperature observation network (HiSAN): Spatial and temporal variations of thermal and wind condition in different climatic condition types

Different patterns of urban development will result in different characteristics of the urban heat island effect (UHI). In order to explore the impacts of urban environment characteristics, wind conditions, and climatic condition types on UHI over different periods, this study adopted Tainan City as the study site, and utilized the surface roughness length and wind prediction, to evaluate the correlation between wind conditions and UHI, as well as the thermal environment affected by different environmental. The UHI characteristics were evaluated by using 100 measurement stations (HiSAN) located in different urban environments. The results revealed the expansion of the daily temperature range was associated with an increase in the eastwest UHI centroid point movement; wind conditions affected north-south shifts of UHI centroid point. The built environments was positively correlate with daytime (0.24) and nighttime (0.68) temperatures. Daytime water bodies notably cool surroundings (correlation -0.52), and green spaces enhance nighttime cooling (correlation -0.64). Wind speed negatively correlates with UHI deviation values during the daytime (-0.17) and nighttime (-0.58). The study highlights the impact of wind speeds and temperature ranges on UHI movement, emphasizing effective ventilation's role in urban cooling and quantifying the importance of water and green space in mitigating UHI.