This study investigates the seasonal variability of groundwater quality and the associated non-carcinogenic health risks from NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}<^>{ - }$$\end{document}and F\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$<^>{ - }$$\end{document} in a semi-arid region of South India. A total of 61 groundwater samples collected during the pre- and post-monsoon seasons of 2020 were analyzed for major physicochemical parameters. Hydrogeochemical ratios, correlation analysis, principal component analysis (PCA), non-carcinogenic risk assessment for different age groups, and GIS-based spatial techniques were employed to identify the controlling processes and assess exposure risks. The results revealed a distinct seasonal shift in dominant cations from Na+ during the pre-monsoon to Ca & sup2;(+) during the post-monsoon indicating the influence of silicate weathering, carbonate dissolution, and ion-exchange reactions. Bicarbonate HCO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}<^>{ - }$$\end{document}and Cl\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$<^>{ - }$$\end{document}remained the dominant anions in both seasons. Temporal variations in Mg & sup2;(+), Na+, Cl\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$<^>{ - }$$\end{document}, SO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{4}<^>{{2 - }}$$\end{document}and NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}<^>{ - }$$\end{document}along groundwater flow paths and across land-use gradients reflected combined geogenic and anthropogenic contributions, with more pronounced impacts during the pre-monsoon period. These interpretations were further supported by geochemical ratios and multivariate statistical results. The Overall Water Quality Index (OWQI) indicated a 36.23% improvement in groundwater quality during the post-monsoon season, attributed to dilution from monsoonal recharge. Health-risk assessment showed that infants and children were the most vulnerable to ingestion-based exposure to NO\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$_{3}<^>{ - }$$\end{document}and F\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$<^>{ - }$$\end{document}, with the highest pre-monsoon hazard quotients observed for infants (mean = 4.51) and children (mean = 2.94), compared with adults (mean = 1.40). Dermal exposure posed a negligible risk for infants (mean = 0.01) and children (mean = 0.14), but contributed a moderate risk for adults (mean = 0.95), particularly in the pre-monsoon season. The study highlights the need for season-specific groundwater management and protection strategies in semi-arid regions. The findings provide critical insights into groundwater quality dynamics and health risks, contributing to the achievement of United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).