Abstract <p>The main hydroclimatic factors of rainfall and mud flood formation have been studied and the spatial distribution of flood hazard of various genesis has been determined within the territory of Slyudyansky district in Irkutsk oblast. The maximum water levels at six gauging stations of the Roshydromet network for 2001–2022 have been analyzed. All cases of floods when critical levels corresponding to the onset of flooding were exceeded have been identified. Flood-forming precipitation and atmospheric circulation features have been assessed for years with floods. It has been determined that the greatest danger is posed by rainfall and mud floods in the Khamar-Daban estuary zone. Mudflow processes are most developed here; there is danger to the towns of Slyudyanka and Baikalsk, as well as to the sludge storage facilities of the closed Baikalsk Pulp and Paper Mill. In 2001–2022, floods were recorded at three gauging stations in 2001, 2005, and 2019. The floods in 2001 and 2019 had a rainfall origin and, in 2005, a mixed snow and rainfall origin. Extreme precipitation (up to 200 mm per day or greater, according to the Khamar-Daban weather station) is the main factor of formation of rainfall floods and mudflows here, along with preceding moistening of the territory during the meridional circulation of the atmosphere. Submontane weather stations reflect the climate of only the coastal strip. The most representative data for a significant part of the river basins are the data of the high-mountain (1442 m a.s.l.) Khamar-Daban weather station, where precipitation is almost twice as high as in the submontane territory. This difference in the amount of precipitation is not taken into account in the analysis of observation data from the weather stations located in the submontane territories. Therefore, for mountain catchments, it is crucial to create an observation network in high-mountain areas where rainfall floods and mudflows are formed, especially where settlements are located in the submontane area.</p>