AbstractIn radiative‐convective equilibrium simulations, convective self‐aggregation (CSA) is the spontaneous organization into segregated cloudy and cloud‐free regions. Evidence exists for how CSA is stabilized, but how it arises favorably on large domains is not settled. Using large‐eddy simulations, we link the spatial organization emerging from the interaction of cold pools (CPs) to CSA. We systematically weaken simulated rain evaporation to reduce maximal CP radii, , and find reducing causes CSA to occur earlier. We further identify a typical rain cell generation time and a minimum radius, , around a given rain cell, within which the formation of subsequent rain cells is suppressed. Incorporating and , we propose a toy model that captures how CSA arises earlier on large domains: when two CPs of radii collide, they form a new convective event. These findings imply that interactions between CPs may explain the initial stages of CSA.