This study examines the implications of climate variability on groundwater for irrigation and agricultural income in the Indian state of Tamil Nadu. Based on a panel of 1740 observations over a 40-year period, it was found that increase in rainfall positively influences the water table, whereas increase in maximum temperature significantly reduces groundwater availability. While increase in temperature has a negative impact on farm income, groundwater availability has a positive impact. Increase in well density has a negative effect, and electricity subsidy a positive effect on farm income. As temperatures increase as a result of climate change, two important practical concerns for agricultural management have been observed: (a) groundwater reduction is likely and alternate sources of irrigation may need to be identified; (b) because richer farmers will be able to invest in deeper wells, small landholders are likely to see lower returns to agriculture with increase in well density. Our findings offer valuable insights into the impact of climatic and non-climatic factors on groundwater level and net farm income that can inform the development of sustainable and equitable solutions.