Using secondary data coupled with real time data, inter-annual variation of surface water salinity in three sectors (western, central and eastern) of Indian Sundarbans during 1984-2013 was studied. Salinity of the aquatic system in the present deltaic complex, situated in the inshore region of Bay of Bengal is primarily regulated by anthropogenic factors (like barrage discharge, run-off from the adjacent landmasses etc.) and natural factors (like siltation, plate tectonics etc.). Surface water salinity has decreased by 0.63 and 0.86 psu per year in the western and eastern sectors respectively, whereas in the central sector, it has increased 1.09 psu per year. Another important objective of the study is to investigate the future salinity (in 2043, 30 years after 2013) in the three sectors of the deltaic complex considering the present data set of 30 years as the baseline. Our forecast through exponential smoothening method reveals an alarming hypersaline environment in the central Indian Sundarbans.