Urban heat island features of southeast Australian towns

This study investigates the magnitude of the urban heat island (UHI) effect in four small towns, with populations of less than 10,000, and one large city, with a population of 3.02 million. All of the experiment sites are located in southeast Australia. Several climatic variables were measured along automobile transects from rural locations through the centres of each settlement. Some transects were repeated at different times of the day. A comparison of long-term temperature records is made from independent sites at one of the towns, and the influence of the UHI effect on the historical temperature record is discussed in a qualitative nature. The maximum UHI effect at the centre of a town over grass is related to population via a regression equation. The urbanrural temperature difference was found to increase with increasing population via the equation ΔTu−r(max)=1.42 log(population)-2.09 The results are discussed in the context of investigations in Europe and North America, and it is suggested that Australian towns and cities are likely to have smaller maximum UHI effects than are observed on the other two continents, for settlements with the same population. The findings of this study have implications for the compilation of historical temperature records and the maintenance of observation networks, particularly for climate change studies.