The growing awareness of the danger of extreme weather phenomena highlights the inadequacy of current cities and the increase in their level of vulnerability concerning the impacts resulting from climate change. The theme of design to combat climate impacts requires the development of knowledge and process models capable of managing the complexity of the information necessary to direct a climate-proof transformation of the urban systems. The research made it possible to develop a methodology based on the exchange of data between GIS-based ICT tools and for parametric design, to analyze the microclimatic and performance behavior of recurrent types of urban open spaces in Italian cities, characterized by different climatic conditions, through generic urban patterns, homogeneous in terms of building density and morphology. The goal achieved was to define the critical aspects of urban open spaces with the performance offered in response to the phenomenon of heatwaves, to verify and measure the performance effectiveness of climate-proof intervention categories, to transfer these results in the form of database, hazard maps, and potential levels of adaptation, and to define guidelines for the climate-oriented project. The transfer of the project data took place through a decision support webGIS platform (SDSS).