The Hydrological Yearbook contains collected and processed data from the network of hydrological and meteorological stations of the Sava River basin and the Adriatic Sea basin, for the territory of the Federation of Bosnia and Herzegovina. At the hydrological stations, water levels are systematically observed and registered, and water flows and temperatures are measured according to a set program. The Hydrological Yearbook is divided into 2 books, namely: Book 1 – Hydrology and Book 2 – Meteorology. Otherwise, the publication of hydrological yearbooks for river basins in the territory of Bosnia and Herzegovina has been carried out since 1919. Since then, hydrological yearbooks have been published regularly and without interruption, within the framework of various state communities.