The present study investigates the impact of climate change on response of hydrologic unit based on global climate models in Upper Wardha catchment, India using statistical downscaling tool (SDSM) and the HadCM3 global circulation model (GCM) A2 and B2 scenario data. Changes in extreme climate which affects the society and the environment is studied by seven indices. Future scenarios (2011-2099) developed for TMIN, TMAX and precipitation (PPT) show an increasing trend for TMIN, TMAX and summer season precipitation after calibration (1969-1985) and validation (1986-2001). With general warming over the area, potential-evapo-transpiration showed increase in loss by 5.9% and 6.24% in 2080s. The overall precipitation shows a decrease with respect to base but 54% and 46% rise in summer rains by 2080s. The downscaled variables were used in HEC-HMS model. After calibrating (1988-2005) the model for daily flows (R2 = 0.72) and monthly flows (R2 = 0.81) and validating (2006-2012) for daily flows (R2 = 0.82) and monthly flows (R2 = 0.96), future flow scenarios were generated.