Digital platforms such as X (formerly Twitter) increasingly serve as arenas for civic expression including during climate related disasters. However, studies on digital governance related critique around climate crises in South Africa are limited. This is whereas the country has a volatile online-offline dynamic where such expressions carry inherent risks. This paper responds by analysing X conversations surrounding the 2022 KwaZulu Natal (KZN) floods. Using a computational social science approach, the paper examines tweets and user accounts involved in propagating high-risk content and situates the dynamics within the risk and digital performativity framework. The study reveals long standing socio-political tensions which are articulated through contested boundaries of digital freedom. This is particularly through xenophobic rhetoric, racialised critique of political actors and antagonism towards corporate institutions. The paper draws on broader comparative cases to contextualise these risks and illustrate the potentially harmful dimensions of digital freedoms during crises. It reveals how the X platform enable civic participation but also backlash and polarisation. These dynamics expose the social vulnerabilities embedded in digital expression cognisant of South Africa’s volatile online-offline landscape. It also calls for further studies on both independent and networked user behaviours to strengthen climate risk communication. The paper contributes to digital humanities by offering a grounded account of how publics contest authority, assert rights, and navigate vulnerability during crisis-mediated online engagement.