WINTER URBAN HEAT ISLAND MAGNITUDES OF MAJOR AUSTRALIAN CITIES

Abstract

This study seeks to determine the relative magnitude of the Urban Heat Island (UHI) effect in
five major Australian cities during the winter season. To achieve this, the study considers three weather
stations in each city: one in a high density urban area, one in a medium density urban area and one in a
nearby very low density urban/rural area. For each station, temperature data were collected every 30 minutes
over a three day period. The data where then plotted and maximum, minimum, and average temperature
differences (and the times of those differences) were recorded. The data show that all of the cities
investigated showed a strong winter heat island effect with the magnitude ranging from about 3o
C up to 8oC.The largest temperature differences typically occurred near dawn (about 6 am) and overnight. It was also
observed that during the day, the high and moderate density urban areas could have temperatures either
higher or lower than the rural areas, a condition consistent with other global observations of the UHI effect.