Streamflow is a vital component of the water resources system and its variation has a significant impact on water supply, flood management, and reservoir operations. Analysing the complex interactions between climate drivers and streamflow will enhance our understanding of the variation pattern of streamflow and to devise appropriate water resources plans. Therefore, the main aim of this study is to investigate the relationship between the potential climatic drivers and streamflow for multiple time scales using bivariate wavelet analysis (BWC) and quantifying the results using average wavelet coherence (AWC). The four prominent global climate indices chosen for the study are the Indian Ocean Dipole (IOD), North Atlantic Oscillation (NAO), El Niño Southern Oscillation (ENSO), and Pacific Decadal Oscillation (PDO). The analysis was done on the Chalakudy river basin, one of the regions widely affected by floods in Kerala. From the results obtained, BWC showed that ENSO has the most influence on streamflow with the highest value (0.51) for AWC which is followed by NAO. Understanding the correlation of streamflow with climatic drivers and considering their influence in studies is important for risk assessment, climate change impact assessment, and ecosystem protection.