Surveys of wellbeing, nature connectedness and pro-nature conservation behaviour scores from adult human participants before and after taking part in nature-based activities, including citizen science, in 2020 are presented. Participants were recruited via a public campaign and were randomly allocated into groups: citizen science, noticing nature (three good things in nature activity), combined citizen science and three good things in nature, and a wait list control. They were invited to take part in activities up to five times in the following eight days. Online surveys of wellbeing and nature connectedness were undertaken at people’s sign up to the project and after the eight days of activities. Demographic characteristics and people’s engagement with the project and responses to the pathways to nature connectedness were recorded after the eight days of activities. The research was carried out to investigate concern about the negative impacts of COVID-19 movement restrictions and social distancing on people's wellbeing and mental health. Research was funded through NERC grant NE/V009656/1 - COVID 19 - Does nature-based citizen science enhance well-being and mitigate negative effects of social isolation? Full details about this dataset can be found at https://doi.org/10.5285/56d4b055-c66b-42b9-8962-a47dfcf3b8b0