Disasters pose a significant public health threat. Current federal disaster management perspectives encourage an approach where citizens become partners in their local communities' efforts to prevent or mitigate the negative consequences of disasters. This dissertation project developed and validated the Citizen Disaster Communication Assessment (CDCA), which is a comprehensive survey instrument measuring individuals' disaster communication before, during, and after the event. The development and validation processes occurred across three studies. Study One consisted of item generation and an expert review. Study Two sought to determine the dimensionality of citizen disaster communication. Study Three surveyed three communities representing different disaster phases in order to examine the relationship among citizen disaster communication, coping, and civic outcomes. Results a) demonstrate evidence of a robust, reliable, and empirically derived citizen disaster communication measure, (b) distinguish citizen disaster communication from other forms of coping, and (c) inform current understanding of how citizens' communication can aid in communities' disaster planning, response, and recovery.