To the article the estimation of dynamic of annual precipitation is driven, maximally possible and total evaporation in the different soil-climatic zones of the Saratov area in the conditions of the global warming of climate. It is shown that in a period from 1981 to 2014 year noted a statistically significant increase in the maximum possible evaporation, which leads to an increase of deficit of evaporation. As a result of the observed tendencies the climate norms of gidromelioration in the area were increased on 200–300 м3 / hectare.
