Rarely are scientific phenomena isolated to a single discipline such as biology, chemistry, physics, Earth science, or others. Rather, these phenomena span multiple disciplines and often require bringing together content and understandings from multiple disciplines to engage with or explain the target phenomena. This study uses a model-based explanations framework to explore high school students' abilities to integrate science content from the disciplines of chemistry and Earth science within the context of generating models to explain a local phenomenon--the urban heat island effect. Students experienced a multiweek instructional unit as part of a larger integrated curriculum that brings together chemistry and Earth science content and features local phenomena to engage students in the scientific practice of modeling. Quantitative and qualitative findings from this study demonstrate students' emerging proficiency with integrating science content, practices, and crosscutting concepts to explain a phenomenon. Students' model-based explanations tended to include phenomenon-relevant components (e.g., physical features of the phenomenon) and sequences (e.g., cause--effect relationships), but tended to include relatively fewer explanatory mechanisms. Implications related to the utility of modeling as a practice-based venue for integrating content from diverse science disciplines are also discussed.