The 1935-2004 time series of the seasonal air temperature and precipitation from 14 weather stations of the Altai Mountains were statistically analyzed. Air temperature time series for the Altai Mountains and for the high and middle latitudes as well as for the Northern Hemisphere were compared. It is noted that at different parts of global climatic cycles the regional responses of seasonal temperature and precipitation changes are unequal. To extend the time series over the past 400 years, mean summer temperature was reconstructed applying dendrochronological methods. Temperature change results in tree-line and glacier dynamics. Mean summer temperature magnitudes at the temperature minimum in the last stage of the Little Ice Age were lower than the present ones by 2, 5° C. There were intervals with the similar warming rate as during the present time, for example, in the second half of the 1800s.