The study aims to evaluate municipal water systems in Tanzania, focusing on their reliability under varying climatic conditions and socio-economic pressures. A multilevel regression model was employed to analyse data from municipal water systems across different regions in Tanzania. The hierarchical structure of the models accounts for both individual-level factors (e.g., population density, rainfall) and regional-level factors (e.g., governance, infrastructure). The analysis revealed a significant positive correlation between annual rainfall variability and system reliability at the municipal level (r = 0.45, p < 0.01), indicating that water systems are more reliable in areas with higher average rainfall. This study contributes to the understanding of how climatic factors impact the reliability of municipal water systems in Tanzania by using multilevel regression analysis. Future research should consider implementing adaptive management strategies based on regional rainfall patterns to enhance system resilience. Municipal Water Systems, Multilevel Regression Analysis, System Reliability, Climatic Factors, Urban Areas