By its position in the Romanian Plain, both Bucharest municipality and its metropolitan area are exposed to several climatic hazards with major impact on the environment. The book assesses the occurrence and the amplitude of the hazard phenomena in the Bucharest Metropolitan Area based on annual, monthly and daily extreme climatic values from all the meteorological stations of concern (1961…2007). Combining and adapting the already existing complex classifications and ierarhizations to the particularities and scale of the study-area, a regionalization of the main climatic hazards was achieved. Relying on the annual incidence and amplitude of the main thermal, pluvial and mixed phenomena as well as on the heat island’s dimensions, the main vulnerability classes were established. Finally, the extreme climatic phenomena were grouped into: climatic hazards within the cold, climatic hazards within the warm semester of the year and climatic hazards occurred all throughout the year.