Atmospheric impacts on daytime urban heat island

Daytime urban heat island effects can be weak compared to night time and even reversed (as in the case of cool islands, where urban locations display lower temperatures than at a rural site), mostly due to shading effects from buildings, vegetation, and other possible obstructions. The study of the relationship between the sky-view factor, an indicator of urban geometry in terms of sky openness, and urban heat island intensity generally focus on night time periods; only a few report on the daytime effect of the SVF. Such effect will also vary according to background atmospheric conditions of the period of measurements. This article is a commentary on a recent publication by the authors on a study of diurnal intra-urban temperature differences in a location with Koeppen’s Cfb climate.