<p>The large fluctuations in the Indian Summer Monsoon Rainfall (ISMR) can lead to extreme climate events like floods and droughts, which in turn affect India’s economic condition. To understand the variability of ISMR on the interannual scale, especially in a future warm climate by the end of the 21st century, we have chosen one of the recent past warm periods, i.e., the mid-Pliocene period (~ 3.2&#xa0;Ma), which was 2–3&#xa0;°C warmer than the pre-industrial era. In this study, we have investigated the Inter-Annual Variability (IAV) of ISMR during the mid-Pliocene in comparison to the pre-industrial period using the CMIP6 model simulations. There is a decrease in the IAV of ISMR during the warm mid-Pliocene relative to the pre-industrial period from all the CMIP6 model simulations. It is found that there is a decrease in IAV in SST over the Niño3.4 region during the mid-Pliocene than in the pre-industrial period. Moreover, the teleconnection between ENSO and ISMR is found to be stronger in the mid-Pliocene than in the pre-industrial period. The IAV in ISMR is highly linked with tropical climate drivers such as El Niño Southern Oscillation (ENSO). We found that the role of Indian Ocean Dipole (IOD) in modulating the IAV of ISMR is insignificant during both periods on the precipitation conditions over the Indian region. However, the impact of IOD on wind patterns is found to be significant during El Niño and La Niña years. In addition, the impact of extra tropical forcing such as the North Atlantic Oscillation and Eurasian snow cover on the ISMR is found to be insignificant in both the warm mid-Pliocene and pre-industrial periods. Therefore, lesser interannual variability can be expected in the future when the CO₂ concentration is constant and the climate reaches the equilibrium state.</p>