Recent studies have reconceptualized infrastructure as comprising both material and social processes, thus offering insights into lived experiences, governance, and socio-spatial reordering. More specific attention to infrastructure’s temporality has challenged its supposed inertia and inevitable completeness, leading to an engagement with questions of the dynamics of infrastructure over different phases of its lifespan, and their generative effects. In this paper, we advance these debates through a focus on the processes of decay, maintenance, and repair that characterize such phases of infrastructural life, by exploring how specific infrastructures are materially shaped by, and shape, social, political, and socio-ecological arrangements. Our intervention has two related aims: first, to conceptualize decay, maintenance, and repair as both temporal phases of infrastructure’s dynamic materiality and its specific affective conditions; second, to trace how these phases of infrastructural life rework embodied labor, differentiated citizenship, and socio-ecological relations. We argue that attention to infrastructure’s “temporal fragility” elucidates the articulation between everyday capacities and desires to labor, the creation of and demands made by political constituents, and the uneven distribution of opportunities and resources.