The paper is devoted to large-scale and zonal atmospheric factors of climate variability over the territory of the Baikal region. This territory is considered to be one of the regions with highest rates of climate change according to Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet). The investigation was made of high- and low-frequency components in multidecadal timescales of climatic indices dynamics on the basis of trend, correlation, and spectrum analyses. The climatic indices determine and distinguish variability in pressure fields and geopotential at high latitudes in the Northern hemisphere, in the northern parts of the Atlantic and Pacific oceans throughout the time period of 1950–2017. Particular emphasis was put on searching for causes of increasingly arid climate in the Baikal region in summer months of 2000–2017, when the number of forest fires in the region rose dramatically. Winds having a southerly component at the height of middle troposphere were identified as the contributing factor for enhancing heat advection.