This paper discusses the results of a comparative analysis of a multiyear time series for average seasonal and annual surface temperatures in Siberia. To analyze seasonal temperature fluctuations, we use the data on average seasonal temperatures which excludes the influence of higher-frequency (cyclonic and daily) fluctuations. We have obtained an empirical correlation between the seasonal fluctuations and average seasonal surface temperatures for two climatic zones (Irkutsk and Tobol’sk). For both zones, the seasonal fluctuations amplitude is, with a high determination coefficient (over 0.9), in linear correlation with the average seasonal winter temperature. We point out that it is promising to model and forecast the observed climatic change on the basis of empirical regularities.