It is generally accepted that climate is an important part of a regions tourism resource base, but its role in determining the suitability of a region for tourism is often assumed to be self evident and therefore to require no elaboration Relatively little is known about the effects of climate on tourism. And even less is known about the economic impact or significance of climate on commercial prospects for tourism. The whole area involving climate related-criteria which people use to make decisions about tourism is largely unresearched, but highly relevant to a variety of applications Thus far, much of the research on climate has been superficial in that relationships between climate and tourism are assumed rather than observed and seldom objectively tested Moreover, the research is largely devoid of any clearly structured conceptual frameworks that embrace important theory, paradigms processes and interactions These frameworks are important because they provide a basis for data generation hypothesis testing and further theory generation Without this, it is difficult to develop coherent research methods, and to develop models that constitute a bridge between the observational and theoretical levels that can assist in building a coherent knowledge base for understanding explanation and prediction In this period of major climate changes, the economical and managerial problems concerning tourism are deeply connected to environmental conditions Climate is a resource for tourism and as such it can be measured and evaluated The precipitations are one of the most important factors, with great impact in the tourism domain. The physico-geographical reality presented in the analysis of rainfall excess and deficit in Sibiu showed that the system operated according to certain mechanisms and processes, and in between certain coordinates, under the influence of different causal factors that vary in time and space. The analysis of the periods with pluviometrical surplus can be done using the Hellmann's method. This approach allows the identification of a possible ciclicity of the episodes with flooding and of those with drought, for a good prognosis in the tourism activities..