Planning a city lab around summer comfort: social learning through rhythmanalysis

Summer comfort in European cities is a growing area of concern, linked to climate change and the urban heat island phenomenon. City labs, which we consider as a subset of real-world labs, are a promising way to bring about transformative change. They imply forms of collaboration and experimentation across different actors in urban spaces. One way of approaching urban planning has been to uncover how users interact with spaces over time, or a rhythm-analytical approach. In this paper, we consider how rhythmanalysis can also be applied to the planning, co-design and implementation of a city lab. Based on an analysis of planning materials generated by researchers and non-academics between 2023 and 2025, and collaborations between researchers and twenty-nine partners, we describe instances where rhythms were aligned and harmonious, and conversely, moments of dissonance where objectives, timing and activities were not aligned. Building on an existing typology of rhythms, we describe moments of harmony and dissonance between organisational rhythms, infrastructure rhythms, but also social rhythms, including cultural norms and expectations. We reflect on how activities around summer comfort in 2025 also had to be planned for in relation to environmental rhythms. In the conclusion and discussion, we draw out key learnings on how a rhythmanalysis of planning a city lab can inform future efforts, particularly in considering the relations between human and non-human actors.