The entry presents the flow of hydrometeorological information that enters the crisis management processes in the Czech Republic. It analyses methods of evaluation of up-to-date meteorological and hydrological data, information and prognostic forecast materials and issuing and spreading of warnings related to dangerous or limit values of meteorological and hydrological events and phenomena via the Integrated Warning Service System (SIVS). It also presents ways of information exchange among crisis management subjects and its cartographical visualization. Within the frame of the SIVS, warning information can be issued on a total of 26 dangerous phenomena divided into 7 groups. A different level of danger can be assigned to each of these phenomena. Based on its intensity, each phenomenon is attributed with one of the three levels of danger (low, high, extreme) distinguished by color in accordance with international projects dealing with presentation of warnings in web pages of national meteorological services. The level of attention required in the given situation from the user, including vulnerability and extent of involved area, is also taken into account.