OBJECTIVE: Natural disasters, such as hurricanes, can contribute to the development of posttraumatic stress symptoms (PTSS), anxiety, and depression. Furthermore, mothers and children are especially vulnerable postdisasters. Despite the rise in the frequency of climate-related disasters and also the threat of disasters (e.g., storms that threaten but do not make landfall), little is known about how predisaster experiences are associated with mothers' and children's postdisaster psychological functioning. This study examined evacuation-related stressors as predictors of mothers' and youths' psychological functioning 3 months after Hurricane Irma. METHOD: Mothers (N = 535; 33% ethnic/racial minorities) from South Florida counties most affected by Hurricane Irma completed an online survey that assessed evacuation-related stressors (both pre- and posthurricane), hurricane exposure (i.e., life threat, loss/disruption), and posthurricane social support and mental health symptomatology (i.e., PTSS, anxiety, depression). Mothers of children aged 7-17 years (n = 226) also reported on their child's psychological functioning. RESULTS: Using a risk and resilience model, evacuation stressors significantly predicted mothers' and youths' PTSS and symptoms of anxiety and depression, even after accounting for demographic factors, hurricane exposure, and availability of social support. Mothers of older children also reported significantly higher levels of PTSS, anxiety, and depression than mothers who only had young children (aged 6 or younger) at home. CONCLUSIONS: Evacuation experiences represent significant stressors that may put mothers and children at risk for PTSS and psychological distress. Resilience-building efforts should include efforts to better prepare families for prestorm evacuations, thereby reducing risk in mothers and youth and ultimately contributing to better psychosocial functioning. (PsycInfo Database Record (c) 2021 APA, all rights reserved).