Groundwater quality is a crucial factor influencing both agricultural productivity and domestic water use, especially in regions heavily dependent on groundwater for irrigation and drinking water. This study evaluates the suitability of groundwater in the Ariyalur District of Tamil Nadu, India, an area increasingly challenged by water scarcity and quality degradation. What sets this research apart is its comprehensive, multi-seasonal assessment of groundwater quality over a three-year period (May 2015–August 2017), covering pre-monsoon, monsoon, and post-monsoon seasons. By analysing key physicochemical parameters—such as pH, electrical conductivity, total dissolved solids, hardness, and various ions—this study provides a detailed picture of the groundwater's suitability for agricultural and domestic uses. Additionally, novel water quality indicators, including sodium adsorption ratio, sodium percentage, residual sodium carbonate, Kelly's ratio, and permeability, are employed to assess potential impacts on soil health and irrigation efficiency. The study's findings reveal significant seasonal variations in water quality, highlighting the critical need for region-specific water quality monitoring and management strategies. This research contributes valuable baseline data that can guide water quality management in semi-arid regions of India and other similar agro-ecological zones, offering insights crucial for sustainable water use and policy-making. The novelty of this study lies in its integrated approach to evaluating both agricultural and domestic water quality within the context of changing seasonal conditions, which has important implications for improving water management practices in the region.