The research is preformed in forest type Quercetum frainetto-cerris on cambisol. In the period of investigation the highest average month temperature of air during the months June, July and August was recorded in 2012. The lowest average month relative air humidity was recorded in August 2012 and it did not exceeded 50%. The content of available water in plants depended on hydrological conditions in particular year. Long periods of drought leads to similar dynamics of water availability in soil. The lowest content of available water in the investigated period was recorded in August.