<p>Computational notebooks are becoming a popular method to introduce mathematics, data, and scientific computing concepts to secondary students. Advocates argue computational notebooks encourage transparency and reproducibility in student work and can enable more personalized investigations of publicly available civic and scientific datasets. However, little is known about how teachers navigate these complex artifacts, let alone how they might support their students in doing so. In this paper, we investigate six pre-service and two in-service K-12 teachers’ sensemaking during a structured clinical think-aloud interview as they engaged with a computational notebook that examines disruptions in local air quality. The notebook presented a common event (annual fireworks) and an extreme event that impacted human health, during which the skies above the greater metropolitan San Francisco Bay region in California, USA turned orange due to wildfire pollution (“Orange Skies Day”, Sept 9, 2020). We examine the ideas that participants engaged as they interacted with the notebooks, and identify three ways in which they interacted with code in the notebook: to make sense of the scientific phenomenon (all participants), to make sense of the available data (6 out of 8 participants), and/or integrate these two dimensions (4 out of 8 participants). We present examples of each of these three forms of sensemaking, highlight their similarities and distinguishing features, and discuss implications for teacher education.</p>