<p>Groundwater contamination is a concern for drinking and domestic supply across India. Escalating volumes of municipal solid waste (MSW) generation, and unsystematic dumping with the rapid urbanization process, enhance these concerns. This study investigates three MSW-affected groundwater systems in diverse climatic regions to elucidate contaminant transport and associated health risks. Objectives include seasonal pollutant analysis, groundwater pollution index (PIG) assessments, and non-carcinogenic health risk evaluations. Three location targets are Kolkata, Durgapur, and Bangalore, which represent urban settlements from Humid to Dry climates. Findings reveal significant pollution levels near Kolkata's Dhapa dumpsite, with approximately 70% of groundwater classified as low pollution risk (PIG &gt; 1 to 1.5). In Bengaluru, nitrate contamination (HQ_Nitrate &gt; 1) poses health risks for 20%, 37.5%, and 66.7% of adults during pre-monsoon, monsoon, and post-monsoon periods, respectively. Similarly, Kolkata's dumpsite exposes 87.5%, 80%, and 62.5% of adults to health risks across corresponding seasons. Nitrate contamination poses health risks to 100% of the children's population near Kolkata's dumpsite, irrespective of season. Whereas HI_Total for the Nitrate, Fluoride and heavy metals combinedly showing all the samples from the three studied cities having potential for human health risk spatially and temporally. Additionally, heavy metal pollution index (HPI) exceeds the thresholds in all samples across the seasons suggest critical pollution levels in Kolkata. This information is vital for effective groundwater management to protect human health, ensure water quality, and quantify potential hydrological contaminants, especially in regions near MSW dumpsites where the demand for groundwater is high.</p> Graphical abstract <p></p>