In Bangladesh, cholera poses a significant health risk. Yet, information about the nature and severity of cholera risk is limited as risk varies over time and by location and changing weather patterns have made historical cholera risk predictions less reliable. In this paper, we examine how households use geographically and temporally personalized cholera risk predictions to inform their water use behaviors. Using data from an eight month field experiment, we estimate how access to a smartphone application containing monthly cholera risk predictions unique to a user’s home location affects households’ knowledge about their cholera risk as well as their water use practices. We find that households with access to this application feel more equipped to respond to environmental and health risks they may face and reduce their reliance on surface water for bathing and washing—a common cholera transmission pathway. We do not find that households invest additional resources into drinking water treatment, nor do we find reductions in self-reported cholera incidence. Access to dynamic risk information can help households make safer water choices; tailoring information provision to those at highest risk could reduce cholera transmission in endemic areas.