Urban nocturnal temperatures, street geometry and land use

The climate in the city of Goteborg, Sweden, was investigated for a three year period. In this paper the nocturnal temperature distribution is analysed in relation to differences in street geometry and land use. The seasonal and monthly air temperature difference between a street canyon and a nearby open area, as well as case studies of the vertical and horizontal temperature distribution within and between different urban units and urban districts are discussed. In spite of a good relationship between the local surface temperature and the sky view-factor, both continuous measurements and case studies show small variations in air temperature within the city centre. Air temperature variations between urban districts of different land use are greater. The average horizontal temperature decrease of 4°C in the transition zone from the city centre to a large park southwest of the centre are, in fact, of the same order as the average urban-rural air temperature difference.