The climate changes occurring on Earth towards warming have affected the territory of Russia, where a greater increase in the temperature of the surface layer of air is observed. For the design, construction and operation of buildings it is necessary to have reliable values of climatic parameters. Traditionally, in Russia, the calculation of climatic parameters is based on the processing of data received from meteostations over a 50-year period. However, in connection with the ongoing warming, the question arose of reducing the period for processing initial data to 30 years. Studies have shown that in the Russian Federation annually various regions and territories are formed, where average monthly or average seasonal temperatures are 4–8 degrees below normal. In addition, trends in temperature changes in different regions are both positive and negative. The analysis of the differences in degree-days and average temperatures of the heating period showed that their difference for the two periods under consideration is insignificant and the decrease in degree-days amounts to an average of 100–15 °C-day across the territory of Russia and an increase in temperature 0.2–0. 4 ℃. Calculations of energy consumption by buildings based on calculated climatic parameters obtained over a period of 50 and 30 years showed that the difference is about 2–2.5%, which lies within the error of engineering calculations. In this regard, it is advisable to leave a 50-year period for processing climatic data from weather stations when calculating specialized climatic parameters for regulatory documents.