The work presents two new 1000-year tree-ring chronologies: Tara (AD 795-2011, the South Chui Range) and Koksu (AD 588-2011, the Katun Range). The calculation of the response function shows that the dominating factor for the radial growth of the tree-ring chronology Koksu is June and July temperature, for Tara is June temperature. The strong correlation between Koksu chronology and meteorological station record in the Northern Mongolia and China at a distance of 300 or more kilometers from the sites of sample collection illustrates summer temperature change at least on a regional scale. At the same time Tara chronology is weakly sensitive to changes in summer temperatures and may be used for dating of geomorphologic, historical and climatic events.