ABSTRACT
This chapter explains how urban climates are modified by both the built forms of urban areas and the urban social, economic, cultural and industrial activities associated with cities. Urban areas modify local climate and thus create novel conditions for both humans and wildlife. The degree of modification depends on the regional situation of the town or city, its size, the density of buildings and the amount and variety of greenspaces and bluespaces. The latter, non-built areas locally lower the impact of the urban heat island. Urban areas may increase thunderstorm rainfalls. They also create places of high wind gusts, though they may lower the regional wind speed. Regional situations affect the propensity for fogs to form, but whether those fogs develop into smogs also depends on human socio-economic conditions and the types of transportation and industrial activities operating in the urban area.
