In recent years, most climate change research have focused on determining patterns of exogenous processes activation and natural environmental and climate variability. This paper presents materials resulted from a comprehensive analysis of historical data, dendrochronological and geotechnical monitoring. The latter was conducted on the Ulaanbaatar geodynamic test site (polygon) (2012–2016) taking into account the geological and geomorphological conditions and using techniques for morphometric analysis of the relief. Some regularities in the development of the gullies and ravines network within the polygon area have been established, specifically, in Ulaanbaatar city and its immediate vicinity. The ongoing natural environmental and climate changes have been estimated according to dendrochronological observations at 26 stations located in most of the territory of Mongolia, except for the Gobi Desert. Activation of exogenous processes is in direct relationship to weather conditions and climate changes. Time series analysis was conducted using the mathematical statistics methods. The verification of the results obtained was underpinned by historical data on the flooding, droughts, and dzud events reported earlier and still occurring in the region, which have always been causing disastrous environmental and socio-economic consequences. The dendrochronological series was 500 years in length, or more, while historical chronology is spanning a period of 400 years. Based on the statistical analysis, the frequency of adverse events was established, and statistical models of weather and climate changes were built, which include predictions of future trends in the course of natural environmental processes until 2050.Keywords: dangerous processes, monitoring, weather and climate change, dendrochronology, statistics.