The present research should assess the high F− concentration evaluating geochemical parameters such as pH and T, in Tirupattur groundwater, South India. For this purpose, groundwater samples were collected from the shallow wells in the study area and analyzed to detect the concentrations of the fluoride and major ions. Results show that a high percentage (60%) of samples has F− concentration greater than 1.5mg/L. The major aqueous species in groundwater are Na+ and HCO3−. The observed positive correlation for F− with pH, Na+, and HCO3− and the negative correlation with Ca suggest their influence on fluoride geochemistry. Evaluation source of these ions indicates that silicate minerals present in the granitic and gneissic rocks are the major origin of F−. The effect of dissolution of evaporates and carbonate is found to be insignificant. However, cation exchange is influencing the Na/Ca ratio in few samples. Aqueous speciation modeling has been developed using PHREEQC. Results indicate that groundwater dissolves more F− minerals provided by Na excess. Further geochemical modeling with variable temperature and pH proved that increase in these parameters changes the chemical kinetics in favor of F− enrichment in groundwater. Considering the temperature range (18.2 to 36.8°C) and alkaline pH along the study area, the high concentrations of Na+ and HCO3− are the major factors determining the release of F− from minerals such as amphibole, biotite, fluorite and apatite in the crystalline formations.