Variation of the Urban Heat Island Intensity over One Year in Putrajaya, Malaysia

This research was conducted to evaluate the variation of the urban heat island (UHI) effects in the planned city of Putrajaya over one year. Putrajaya, the administrative capital of Malaysia, is known for its meticulous town planning. The main observations are temperature variation, the changes in wind speed, percentage of relative humidity, and subsequently, the intensity of UHI in the research area. Putrajaya Corporation Complex Precinct 3 (P3) and Precinct 9 (P9) are located in the central business district (CBD) and residential areas respectively. These two places are representatives of UHI's effects on CBD and residential areas. Ultrasonic anemometers which measure 3 components of wind velocities and temperature were employed to analyse temperature and wind patterns. The result indicates the city experienced high temperatures during the day causing human heat stress and discomfort. The UHI intensities of the city are within the range of temperature differences 2 to 3 °C. Land surface cover and numbers of the population are the vital effects of the UHI. Thus, strategies to reduce the existing high air and surface temperature are required in the future.