Climate change is one of the major environmental challenges of the present era. Among the key climatic parameters, atmospheric humidity plays a crucial role in defining weather conditions, agriculture, human health, and various economic activities. Therefore, This study explores the forecasting of relative humidity (RH) as a significant factor in hydro-climatology using the ARIMA(0,1,1) model. The research utilizes historical RH data from 1993 to 2022, coupled with the Mann-Kendall test for trend analysis and time series techniques, to evaluate both past and future RH trends. The results indicate that while RH experienced a decreasing trend over the past three decades, this trend was not statistically significant because of Z statistical equal= -0.01 that is fewer than 1.96 threshold. Further analysis using the ARIMA model forecasts a slight increase in RH in the coming years. These findings suggest that, despite the absence of significant past trends, RH may show modest upward changes, which could influence future hydro-climatic conditions. The study highlights the importance of incorporating RH forecasting into hydro-climatological models for more accurate predictions of climate behavior and water resource management. Additionally, the research underscores the utility of time series analysis in understanding long-term climate variables and their implications for environmental planning.