Problem setting. One of the complex and controversial theoretical issues is the meteorological division and construction of the taxonomy of parts. After all, humanitarian and social subjects, due to their own specifics related to their existence, need other grounds for distribution. Thus, the study of the taxonomy of parts and its logical principles in meteorology will help to deepen the understanding of the specifics of the humanities and social sciences and the development of the logical basis of the methodology of the humanities. Recent research and publications analysis. Analysis of sources of origin, modern theoretical works on meteorology indicate unresolved issues regarding the taxonomy of parts, the possibility of involving mathematical set theory, doubts about the stability of the principles of part ratio, the problem of identity and more. Paper objective. The purpose of the study is to consider the problem of division of the whole into parts and the principles of construction of the taxonomy of parts, the reasons for their stability or doubt in meteorology. Paper main body. Mereological structure consists of a whole and parts. Parts can be constituent elements, components, ingredients, portions, aspects, parties, members, etc. Parts can be considered in the abstract (as a part in relation to any whole) or in relation (taking into account the function, ie as a component of the whole). Parts can be concrete or abstract. When analyzing the types of parts, there may be a problem of identity. The order of the parts, their distribution and relationship are determined by reflexivity, transitivity and antisymmetry. All three principles – reflexivity, transitivity and antisymmetry, together with taxonomy appear as the theoretical basis of classical meteorology. Conversely, in nonclassical meteorology, arguments are developed regarding doubts about the stability of these principles. Additional principles are the principles of composition and decomposition. Extensional mereology demonstrates its limitations in relation to living objects. Conclusions of the research. The article analyzes the types of parts, the principles of their relationship, doubts about the stability of these principles and their assessment of the identity of parts and the whole. In our opinion, this opens the possibility of further distinguishing between extensional mereology and meteorological approach in hermeneutic logic, which determines the further success of building an authentic logic of humanitarian and social cognition.