Online citizen science platforms for nature observations provide valuable data for nature enthusiasts and scientists, but typically emotions and feelings experienced in nature are not shared there. Through focus groups with users of the Dutch citizen science platform Waarneming.nl, we explored how affective nature experiences are shared. We found that citizen scientists exchange affective experiences through face-to-face conversations or social media and hear about others’ experiences through traditional media. Affects are shared to enthuse others to go into nature, respect or connect more with nature, feel recognized and cope with varying affects experienced in response to environmental loss. Yet, these affects are generally not shared on platforms like Waarneming.nl as these media are associated with knowledge production, science and policy, which users perceive to be in opposition to affect. We reflect on this perceived tension between science and affect, suggesting potential ways to overcome this.