This paper demonstrates that local knowledge systems are inherent elements of people's capacity to forecast natural hazards and thereby reduce disaster risk. It describes the local knowledge systems prevalent among traditional fishworkers in Kerala to predict and forecast coastal hazards. Apart from diverse techniques of participatory inquiry, in-depth interviews were carried out with 400 fishing households across 20 marine fishing villages of the state. The socially constructed nature of coastal hazards is demonstrated as a holistic phenomenon namely kolu. The empirical knowledge related to forecasting and prediction of kolu is thus explained in terms of biotic, oceanic, atmospheric and celestial spheres. This paper asserts the need for effective community-based early warning systems that are deeply embedded in the livelihood struggles and life-world of marginalised resource-dependent communities.