Microclimate and Downtown Open Space Activity

Microclimatic conditions in business district open spaces tend to be more extreme than prevailing weather conditions. Although the buildings are chiefly responsible for this inclemency, their shapes and arrangement could also potentially be used to moderate or enhance prevailing conditions. To provide better guidance in design, we need to know how humans respond to microclimatic conditions. In particular, we need to know first how sunlight, temperature, humidity, and wind combine in sensations of outdoor human comfort, and second, how important microclimatic factors are in behavior. This article reports on a study of revealed preferences for certain local climatic conditions, measured in terms of presence levels and activities in seven closely spaced corporate plazas and public squares in a built-up, downtown area. The observations were conducted over a 5-month period. The measured microclimatic conditions accounted for most of the variance in activity levels and types. Temperature was the single most important variable. Although great variation in level of use among spaces cannot be explained solely in terms of microclimatic differences, use within spaces varies chiefly as a function of microclimate.