Understanding young people's lives through a focus on their micro‐geographies has been central for exercising young people's voices through research. However, such a focus has also neglected the multiple and complex realities of growing up that ripple throughout their lives, resulting in calls for more research to go beyond capturing daily snapshots of experience. This paper acknowledges that decades of research with and for young people living on city streets has underpinned activism and challenged western child rights discourse, helping to ensure that abuses and violations of street young people's rights are confronted. Yet, much of this research draws attention to lives lived in present moments – the difficulties encountered and capabilities displayed. It does not account for the temporal fluidity of how young people's realities are future impacted by slow crises and challenging daily life experiences as they grow towards adulthood. This paper explores the crisis temporalities of young people's street lives through a youth‐led ethnographic longitudinal approach. The paper focuses on 18 youth researchers and over 200 of their peers' experiences of research over three years while living on the streets of three African cities. The paper discusses the challenges of undertaking longitudinal research alongside the temporal affordances of surviving urban informality and the compounding effects of slow crises on present and future‐oriented survival. These affordances emerge as street youth respond to daily trials, experience setbacks, crises, triumphs, and failures, yet show resilience and employ capabilities. The paper concludes by demonstrating the crucial importance of ethnographic longitudinal research for policy and practice to ensure that youth who age on the streets, and their families, are supported in accordance with social justice concerns.