In this paper, we argue for an approach that goes beyond an institutional reading of urban climate governance to engage with the ways in which government is accomplished through social and technical practices. Central to the exercise of government in this manner, we argue, are ‘climate change experiments’– purposive interventions in urban socio-technical systems designed to respond to the imperatives of mitigating and adapting to climate change in the city. Drawing on three different concepts – of governance experiments, socio-technical experiments, and strategic experiments – we first develop a framework for understanding the nature and dynamics of urban climate change experiments. We use this conceptual analysis to frame a scoping study of the global dimensions of urban climate change experimentation in a database of 627 urban climate change experiments in 100 global cities. The analysis charts when and where these experiments occur, the relationship between the social and technical aspects of experimentation and the governance of urban climate change experimentation, including the actors involved in their governing and the extent to which new political spaces for experimentation are emerging in the contemporary city. We find that experiments serve to create new forms of political space within the city, as public and private authority blur, and are primarily enacted through forms of technical intervention in infrastructure networks, drawing attention to the importance of such sites in urban climate politics. These findings point to an emerging research agenda on urban climate change experiments that needs to engage with the diversity of experimentation in different urban contexts, how they are conducted in practice and their impacts and implications for urban governance and urban life.