Drought has significant impacts on civilization, but it is a difficult phenomenon to monitor, predict, and even to define. Nations and organizations have developed many drought monitoring, response, and prediction tools over the decades to address these issues. The international community has long recognized the importance of developing a drought early warning system (DEWS). A DEWS should collect and analyze information and disseminate the information and analyses in a timely manner so that decision-makers may effectively prepare for and respond to drought. National and regional DEWS have been developed in recent years, and it is only lately that a concerted effort has begun to develop a global drought early warning system, which starts with the creation of a global drought information system (GDIS). As more nations move forward with the creation of national drought policies focused on risk reduction, it is imperative that effective drought early warning systems be implemented to support these policies.