This study analyzed the weather environment of the smart city to identify the temperature reduction effects of the heat reducing facilities. The methodology is divided into indoor and outdoor analyses. Indoor analyses were conducted for the evidence-based design of the facility. The size of nozzle is adjusted to derive the most efficient size for outdoor use. Three types of nozzles were used, 0.15 mm, 0.2 mm and 0.3 mm. The most efficient nozzle was selected as 0.15 mm. The outdoor test was measured for two days from August 3 to August 4, 2020, and the weather data were collected for the control and target sites on the first day. On the second day, the measurements were taken assuming that the temperature and humidity of two sites would be similar. Compared to the control group, the outdoor test site had a temperature reduction effect up to 7.4℃. When operating the heat-reducing facility, the rate of change in sensible temperature is lower than control site. This study concluded that mist facilities have a pre-cooling effect, which means reducing the temperature to a certain level. The results from this study data could be provided when establishing an adaptation policy for a heatwave.