This paper reports on a longitudinal study investigating the impact of long-term regular outdoor learning in mathematics in the school-grounds. An interview-based case study of John, a lower secondary school student, will be analysed. The case study will describe John's perceived experience of long-term regular outdoor learning in mathematics and its impact on affective and academic factors. The findings emphasise the positive outcomes of long-term regular outdoor learning in mathematics, indicating enhanced cooperative learning, reduced mathematics-related stress and anxiety, changed self-concept, and enhanced mathematical proficiency.