moc.zip: This dataset was used to calculate the meridional overturning water-mass stream function (Fig.2) and net evaporation which are responsible for net precipitation over the South Asian landmass during June to September months (Fig.3). track_amp.zip: The vertically integrated horizontal water-mass flux was computed from this data (Fig.4). bob_path.zip: Net precipitation (Fig.5) and net evaporation (Fig.6) calculated from Lagrangian water-mass trajectories that have crossed over the Bay of Bengal at least once and fallen down over the South Asian landmass. Also, Table 2 was prepared using this data. evap_precip_basins.zip: This file contain datasets that were used to compute the contribution of separate basins to the South Asian summer monsoon precipitation (Table 1) and also how the spatial distribution related to each basin (Fig.7) interannual.zip: Interannual precipitation variability was obtained from this dataset.