The objective of this paper is to present results of different experimental investigations of urban climate's thermal component in Freiburg, which were carried out in order to get climate data for urban planning. Freiburg is a city with about 200000 residents in the southwest of Germany. Due its location in the river Rhine's valley and influencing by local wind systems caused by the near black forest, urban climate plays a dominant role in urban planning of Freiburg.
The investigations were performed in the canopy layer within different urban microclimates because that is the space where people are living and which is therefore relevant for urban planning. Using a special mobile measuring system the meteorological parameters air temperature, air humidity, wind velocity and both short-wave and long-wave radiation fluxes were recorded on hot summer days in order to characterize different urban microclimates' thermal component during an extreme weather situation which is responsible for human heat stress.
On the basis of a thermophysiologically significant index derived from the human energy balance, temporal and spatial variability of thermal sensations of human beings within the different urban micro-climates will be assessed. Taking into consideration results from analogous investigations, results obtained here are discussed with regard to their application in urban planning.