Abstract <p>Soil changes in the periglacial regions of Western Siberia and East European Plain (from arctic tundra to subtaiga) in response to climatic fluctuations during the Late Glacial and Holocene (the last 15 ka) are considered. The changes caused by climate cooling and warming, such as the formation of second humus horizons, development of postcryogenic structures, and others have been studied. The main focus is on the impact of temperature regime changes, since these are the trends that are to be expected in the near future. In the north of Western Siberia, on the islands and coast of the Kara Sea, the thermal maximum dates back to the Allerød–Preboreal. Moreover, in this area, unlike Europe and the North Atlantic, the cooling of the Younger Dryas is not detected. Further south, in the taiga zone, the thermal maximum shifts to the Early and Middle Holocene. In the Arctic part of Western Siberia, the thermal maximum is associated with the early stage of peatland formation 14–11 ka ago favored by the increased temperatures and sufficient moisture supply in the Late Glacial and Early Holocene (the time of climatic optimum for this territory). In the south of the forest zone and in the forest-steppe (Vasyugan area), peatlands did not develop in the first half of the Holocene due to the lack of moisture. The maximum peat accumulation has taken place during the period of climate humidization in the last 4000 years. Significant changes in pedogenesis are related to climate warming in recent centuries. In the south of the forest zone in Western Siberia, thick hortic horizons are found, the formation of which was caused by the cooling of the Little Ice Age and the need for abundant application of manure with an admixture of ash and fine earth. As a result of recent climate warming, the need for these technologies has disappeared, and the formation of the hortic horizon no longer occurs.</p>