The article examines the artistic features of the image of a thunderstorm in Dostoevsky‟s novel “The Idiot.” The theory of symbol developed by A. Losev and S. Averintsev, the idea of psychological parallelism in a literary text studied by A. Veselovsky and the theory of the polyphonic novel by M. Bakhtin were used as a methodological basis. A significant part of the article is devoted to the poetics and symbolism of the pre-storm landscape in St. Petersburg and the peculiarities of describing the inner state of Prince Myshkin. The relevance of the work is determined by the importance of considering the philosophical and aesthetic nature of the landscape (including urban landscape) in the writer‟s polyphonic novels, in particular, in “The Idiot.” Dostoevsky‟s landscapes fully reveal the spiritual and moral-philosophical facets of the author‟s worldview and his characters. This is especially true of the pre-thunder and thunderstorm description of nature in the novel. They are subtly coupled with the image of Myshkin‟s psychological state before an epileptic seizure. The pictorial power of Dostoevsky‟s artistic word in this episode often attracted researchers, but it did not become the subject of a detailed consideration. That is why a detailed analysis of chapters 2-5 of part II of the novel, in which the thunderstorm, the experiences and thoughts of the main character are outlined, was claimed by us as the main purpose of this article. To achieve the study‟s goal, we used the following methods: a) systematic analyses, combining historical-literary and theoretical-literary approaches; b) structural analyses, combining the semantics, poetics of the artistic word and the concept of culture and literature as a focus of signs and symbols; as well as the methods of observation, description, contextual analysis, analysis of the unity of form and content. The conclusions of the study allow us to use the terminological combination of A. Veselovsky “psychological parallelism” in relation to the analysis of the thunderstorm episode and the description of Myshkin‟s seizure. It is proved that the polyphonic instrumentation permeates both the content and the form of Dostoevsky‟s text, and the symbolism of the fragment of the pre-storm and thunderstorm is extremely multi-layered.