The data provides the explanation to the process of building a socioeconomic development model for a municipality in Poland. This data set explains the steps taken in order to reach to an indicator that interprets a local socioeconomic development as well as it provides a hint of methodology selection. We set the hypothesis that the introduction of a geothermal spa accelerates the socioeconomic development of the municipality in which it is established. This assumption is to be verified by socioeconomic development empirical observations of selected locations in Poland that have geothermal water parks in years 1995-2015. Further statistical procedures (Principal Component Analysis, switch regression model) help to verify the research assumption. A constructed indicator of local socioeconomic development undergoes observation together with the geothermal water parks parameters we develop as well. As a result we attempt to confirm the main hypothesis of our research. The data that serves to build the socioeconomic development model of a municipality is obtained from one source i.e. Central Statistical Office in Poland.