Water resources are among the most vulnerable sectors to climate change, as variations in precipitation, temperature, and humidity directly influence water availability and security. The hydrological cycle’s sensitivity highlights the importance of sustainable water management, particularly in water-stressed regions. Jharkhand, a mineral-rich state in eastern India, is highly exposed to climate variability due to erratic weather patterns, limited adaptive capacity, and growing industrial and urban pressures that threaten forests and groundwater resources. This study investigates long-term climate trends in the Palamu division of Jharkhand, focusing on the districts of Garhwa, Latehar, and Palamu. Daily climatic data from 1981 to 2021 were analyzed using the Mann–Kendall test, modified Mann–Kendall test, and Sen’s slope estimator in R-studio, considering maximum temperature, minimum temperature, specific humidity, and precipitation. Results reveal distinct trends across districts: The annual maximum temperature increased slightly in Garhwa (0.001 °C/year) but showed a marginal decline in Latehar and Palamu (− 0.0014 °C/year). In contrast, the annual minimum temperature displayed a consistent rise in all three districts, with higher rates in Latehar and Palamu (0.0156 °C/year) compared to Garhwa (0.0151 °C/year). Specific humidity exhibited a significant upward trend across districts (0.0322–0.0343/year), while annual precipitation also showed increasing tendencies (0.4462–0.6534 mm/year). These findings suggest a warming trend in minimum temperatures, rising atmospheric moisture, and enhanced precipitation, which together may have positive implications for regional water availability. However, the uneven spatial distribution of climatic changes underscores the need for localized water management and adaptation strategies to ensure long-term sustainability.