Several climate models indicate an increase in the occurrence of severe thunderstorms in the Southeast region of Brazil, highlighting the importance of determining vulnerable areas to provide logistical support to agencies that work with victim assistance. A large number of natural disasters were recorded, in Sao Paulo state on the rainy season of 2009/2010 hydrological year. A search was carried out on the IPMET severe events database for significant occurrences triggered by precipitation. A synoptic description of the meteorological condition of the period is presented. The damage related to flooding and mass movements events were spatialized in São Paulo. Moreover, a systematic search for quantitative precipitation data was performed. The probability of occurrence of these events was determined using the usual hydrological resources, IDF equations. The difficulties to associate events with damage occurrence with precipitation threshold are discussed.