The objective of this work is to analyze the temporal and special series of rainfall for the month of October in the catchment area of Alto Jacuí / RS. The study area, located in the Guaíba Hydrographic Region, covers an area of 12,985.44 km². For this research, 27 pluviometric stations were distributed throughout the study area. This data was tabulated and organized in Excel 2013, where you can calculate the average and generate tables and graphs. For the average precipitation of the month of October, the sturges technique was used to select the classes and the ArcGIS software for the interpolation. As a result it obtained the average of 194.9 mm. When analyzing the mean of the temporal and spatial historical series of the rainfall for the month of October in the hydrographic basin in the Alto Jacuí it can be seen that the temporal distribution has greater variability than the spatial distribution. Thus, the temporal distribution is affected by larger scale phenomena, such as the ENSO phenomenon (La Niña and El Niño). However, the spatial distribution is influenced by the displacement of the Cold Fronts passages, together with the altitude effect.
