Long-term temperature conditions of 3,2 m thick soil layer are studied based on the data of Transbaikalian weather stations. Among all the thermal factors, the most informative one, the smallest monthly mean temperature in the annual cycle at the standard measurement depth, is used. Its vertical profiles reflect the depth variations of the temperature and its spatial diversity. They constitute the base for a newly developed graphical classification scheme for wintery thermal conditions of soils. It includes five types of the thermal conditions: moderately cold, cold, very cold, severe, and extreme. They are all indicated in the orographic scheme at the areas of temperature measurements. Cartographic models of this type are especially topical for the case of rather complicated relief of Transbaikalian highlands. The models can reveal tendencies in geographical differentiation of the soils’ thermal conditions. In spite of the thermal field inhomogeneity, the trend of increasing wintery cooling of soils from south to north is pronounced. The very cold condition is the main type of the soil’s state in the southern Transbaikalia while the severe and extreme status is typical for its northern part. On the one hand, this method opens a perspective for broadening the spatial picture of the soils’ thermal conditions and, in spite of the possible difference in the factors controlling the soil temperature, the method can be applied for other regions with contrasting landscape-geographical situation. On the other hand, the differentiated estimation of the current thermal state of Transbaikalian soils we obtained can be used for choosing the most effective ways of nature protection policy adjustment to the enhanced climate aridisation and anthropogenic affecting the nature, especially in the modern agricultural land tenure of steppe landscapes.