It is difficult to measure precipitation due to spatial and temporal variability. In this study we analyzed the variability of precipitation of high- and low-rainfall regions in Bangladesh using Precipitation Concentration Index (PCI) from the data of two meteorological stations. We compared PCI values for various periods such as annual, supra-seasonal, seasonal, three and two-months. Most previous studies have analyzed the long-term precipitation in Bangladesh. We analyzed the variabilities from long-term to short-term and tried to characterize the irregular precipitation. In the result, the precipitation in Bangladesh was mostly concentrated between two and four months of the year. Future research will require more station data to understand the more detailed precipitation patterns in Bangladesh.