Objective: To determine whether students who engage in a sedentary task in an urban park-like setting experience improved mood and whether this effect is moderated by mindfulness meditation. Participants: 234 (133 females) undergraduate students, who either engaged in outdoor recreation frequently or infrequently. Methods: Participants engaged in 20 minutes of mindfulness meditation or a control task, either in a campus park-like setting or in a quiet room indoors. Before and after the activity, total mood disturbance (TMD) was assessed with the Profile of Mood States Questionnaire. Results: Being outside or meditating reduced TMD for those who frequently recreated outside. Those who infrequently recreated outside experienced decreased TMD if they meditated inside and increased TMD if they did not. When outside, TMD decreased regardless of activity. Conclusions: Spending time outside and practicing meditation may be effective approaches for improving college students' mental health, particularly for students who infrequently go outside.