Age differences in posttraumatic stress disorder (PTSD) are widely researched, but findings remain inconclusive. The mixed findings may in part result from sampling participants exposed to different trauma types at different times. Here, we controlled for this issue by sampling participants exposed to the same devastating hurricane. A total of 1.5 months after Hurricane Florence (T1), we asked 174 adults living in two severely affected states to describe their hurricane experience and fill in measures of PTSD and event centrality. Then, 7 months after the hurricane (T2), participants were reinvited to the survey, and 98 filled in the same questionnaire. The hurricane descriptions were coded for level of exposure severity. When controlling for trauma characteristics, including level of severity, younger age significantly predicted PTSD at T1 but not T2. When also controlling for event centrality, younger age predicted PTSD at both measurement times. Moreover, from T1 to T2, young adults significantly increased how severely they described their hurricane experience to be, whereas such amplification was absent in the older age groups. Overall, the findings provide some evidence that younger age increase vulnerability for PTSD and increase the perception of trauma severity over time.