Urban-rural temperature differences in coastal cities: influence of rural sites

This paper considers problems in calculating the heat island magnitude of coastal cities. We examined the influence on heat island magnitude (1) when a rural observatory located in an inland area is compared with an urban observatory and (2) when an observatory in an atypical countryside setting is chosen as the rural site. The results showed that the urban–rural temperature difference was bigger in winter than in summer when the rural observatory was located in a relatively inland area in comparison with the corresponding urban observatory. This tendency was more marked at night than in the daytime. When an observatory in an atypical rural setting was used, the urban–rural temperature difference was greater from 11:00 p.m. to midnight in summer. Therefore, only observatories located in typical rural areas and located roughly the same distance from the sea as the corresponding urban observatories should be selected for investigation of urban heat island magnitude. Copyright © 2005 Royal Meteorological Society