This paper attempts to characterize regional drought using 0.5 degree reanalyzed GPCC (Global Precipitation Climatology Center) gauge-based gridded monthly precipitation data sets in Korea. Drought is a function of precipitation and long-term observed precipitation was performed to enhance this characterization. There are limited long-term records from each station, therefore, a global gridded data set has been employed. Before using this data, 10 corresponding grids with KMA (Korea Meteorology Administration) stations were validated through cross-correlations (0.93–0.99). The impacts of drought are dependent on its duration, severity and spatial extent. Drought occurs when a below average water availability persists and becomes regionally extensive. In this study, 66 GPCC gridded precipitations were employed to estimate the effective drought index along with the available water resource index. The results of the 10 KMA corresponding stations were as accurate as those of the global data. Consequently, gridded data are suitable for a monthly drought severity investigation. In addition, spatial distribution of drought and available water resources were exposed by kriging interpolation technique over Korea. Through this study, drought risk city Taebaek in Kangwon province was classified by its 2009 intensity of monthly precipitations, droughts and available water resources.