Agricultural drought has always brought serious problems related to food production in the State of São Paulo, Brazil. The scope of this study was to adapt the methodology of the Standardized Precipitation Index (SPI) to the historical values of Actual Evapotranspiration series fitted to the beta distribution, to quantify agricultural drought in the State of São Paulo. The new index is named Standardized Actual Evapotranspiration Index (IPER). The results indicates that such new index, IPER, is vey useful to the "near real time monitoring" of the agricultural drought in a ten day period. It was observed that the range of this new index is directly related to the numbers of standard deviation for which a given value of actual evapotranspiration is below of its expected value, indicating the intensity or severity of the agricultural drought.
Standardized Precipitation Index; near real time monitoring
