In an era characterized by fast and drastic global changes, the scientific community highly values the long-term dimension of environmental monitoring programmes. This article focuses on the affective dimension of the management of these programmes when specifically involving volunteers during their working time. Drawing on an empirical study of two such programmes in France, this article studies the long-term related emotions of the programme managers and participants, as identified and expressed by the managers themselves, and analyses the emotional work they perform. Two long-term related emotions appear to be particularly important in their work: hope and boredom. Both can have a positive or negative effect, depending on the emotional work involved. Managers attend to them by making data collection protocols less wearisome, by “finding the short term in the long term”, and by creating “hot moments”. More generally, we show that managing environmental monitoring programmes over an indefinite duration is affectively demanding, especially in a professional setting where managers and participants expect to produce practical outcomes in the short term. There are no ready-made recipes and managers must adapt their emotional work to each programme's specificities. The capacity to identify and attend to emotions is therefore a crucial quality of the managers of these programmes.