In the smart cities context, using green roofs can contribute to making cities more resilient, mitigating effects in the urban thermal field, such as urban heat island. In addition, mesoscale models of weather forecasting can contribute to short-term decision-making by public managers. Thus, this work presents an analysis of the impact of green roofs in Chilean Mediterranean cities, with this modeling tool, on meteorological variables. These cities are considered small and medium-sized. The results shows that the green roof reduces the temperature in Talca by up 1.28 °C, while the coastal city of Concepción decreases up to 0.1 °C. The turbulent kinect energy also reduces with the presence of vegetated roof compared with conventional roofs, influencing in the dispersion of pollutants. In general, the intensive use of green roofs in clusters of small cities can act as moisture and heat suppliers due to the advection effect, thus contributing to mitigating heat island effects.