Assessing a Small Summer Urban Heat Island in Rural South Central Pennsylvania

The development of cities potentially has a significant impact on climate. Buildings and infrastructure that replace natural vegetation often create new microclimates through changes in the energy balance associated with the built environment. The urban heat island effect, the phenomenon where air temperatures within an urban area are warmer than the surrounding rural areas, has been thoroughly examined for large urban areas. The purpose of this study is to determine the magnitude and extent of the urban heat island for a small urban area surrounded by agricultural land. Temperature data collected from several urban and rural locations over a four-month period indicate that urban areas are, on average, 0.8°C warmer than rural areas. The average difference between the most urban and most rural stations was 1.9°C. The maximum difference between these same stations was 10°C. Initial results, requiring further inquiry, suggest that the magnitude of the urban heat island is smaller during the summer season compared to the spring and fall.