We study the weak $K_s$-saturation number of the Erdős--Rényi random graph $\mathbbmsl{G}(n, p)$, denoted by $\mathrm{wsat}(\mathbbmsl{G}(n, p), K_s)$, where $K_s$ is the complete graph on $s$ vertices. Korándi and Sudakov in 2017 proved that the weak $K_s$-saturation number of $K_n$ is stable, in the sense that it remains the same after removing edges with constant probability. In this paper, we prove that there exists a threshold for this stability property and give upper and lower bounds on the threshold. This generalizes the result of Korándi and Sudakov. A general upper bound for $\mathrm{wsat}(\mathbbmsl{G}(n, p), K_s)$ is also provided.