Purpose: to substantiate the prediction of the moisture content of the roadbed, taking into account the peculiarities of climatic conditions in the territory of southwestern Kyrgyzstan. Southwestern Kyrgyzstan (Southwestern Kyrgyzstan), one of the four climatic provinces of Kyrgyzstan. The main source of soil moisture is precipitation. Precipitation is very variable in time and space in the study area, and therefore the identification of their altitude dependencies in the mountains is a difficult task with an insufficient amount of initial data, which is directly affected by moisture accumulation of the roadbed. All engineering measures to regulate the water-thermal regime are based on limiting the water-thermal regime, as well as limiting the access of moisture to the roadbed, and proper planning of these measures is carried out only if the sources of humidification of the area are carefully established. Methods: forecasting the moisture content of the soil of the roadbed with a sufficient degree of reliability allows you to predict the spring or autumn moisture content of the soil of the roadbed using a mathematically justified analysis of weather and climatic factors of the foothill and mountainous zone. Results: the task of this work is to develop a methodology for predicting the moisture content of clay soils of the roadbed of the 1st type of terrain, taking into account the nature and degree of humidification of foothill and mountainous terrain for the territory of southwestern Kyrgyzstan. Practical significance: this technique is used in the design, as well as during the operation of the pavement on the territory of southwestern Kyrgyzstan with a sufficient degree of reliability to predict the spring or autumn moisture content of the soil of the roadbed using a mathematically based analysis of weather and climatic factors. An analysis of direct observations of soil humidity and temperature was carried out, during which it was shown that humidity and Selyaninov’s hydrothermal coefficient (GTC) are related by a regression equation. As a result, equations were obtained for calculating the relative humidity of the soil in the foothill and mountainous road-climatic regions of southwestern Kyrgyzstan.