Sensation-seeking is the seeking of varied, novel, and intense experiences and the willingness to take risks in order to engage in these experiences. Sensation-seeking is robustly associated with engagement in risky behaviors but important questions remain concerning the role of within-person variability in sensation-seeking. We use data from a 21-day daily diary protocol from 167 participants (mean age = 25.37, SD = 7.34) to test day-to-day, within-person associations between sensation-seeking and both alcohol use and self-reported risk-taking. Participants also reported the riskiest behavior they engaged in each day, allowing insight into the types of risks that participants take during the course of daily life. Multilevel model results indicate that days of higher than usual sensation-seeking are more likely to be days on which alcohol is consumed relative to days of no alcohol use, and that risk-taking is higher than usual on days of higher than usual sensation-seeking. Coupling natural language processing with network science tools, we reduce 2490 self-reports of the day’s riskiest behavior to 20 communities reflecting a wide range of risk domains, including social, school, work, and drug use risks. Creating a risk-taking diversity score based on the identified domains of participant-elicited risk behaviors, we find that trait sensation-seeking is positively associated with greater diversity in the types of risks reported. In sum, we capture day-to-day fluctuations in sensation-seeking, observe that sensation-seeking and both alcohol use and risky behaviors are associated at the within-person level, and provide insight into the types of risks taken during the course of daily life.