The spatial and temporal patterns of ground-level air temperatures in Bolzano were recorded from 01/05/2012 to 31/10/2012 with twelve rural and four urban weather stations. A number of additionally collected climatic variables and specific site factors should allow the interpretation of the temperature patterns and provide an explanation for significant temperature differences between the sites.
Among the additional factors mainly land use (fruit, wine, grass) as well as the distance to the city limits show a correlation with the rural temperatures at a height of 200 cm. Without the elevation correction altitude shows a strong correlation too. Even when comparing the temperature differences of rural and urban locations, a link to land use and distance to the city limits (as well as the altitude) could be established. According to the results of a multiple regression, however, the main factor is the soil temperature, followed by global radiation.
Soil temperature, global radiation, land use and the distance to the city limits therefore determine the energy balances of the individual sites and thus the near surface air temperatures. The influence of the individual factors is, however, not constant during the day. This is the reason why Bolzano represents an urban heat island at night with only little temperature differences during the day compared to its surrounding area.