This dataset supports the study "Unpacking intermunicipal climate adaptation networks in Arctic Norway". This study investigates how intermunicipal networks support climate change adaptation (CCA) in Arctic Norway, where municipalities face both limited capacity and accelerating climate risks. Drawing on survey data and a boundary-spanning framework, we categorize network activity across four dimensions: organizational form, adaptation focus, risk type, and priority level. Our findings reveal strong regional clustering, particularly in the Lyngenfjord region, and show that CCA is often a secondary objective within networks primarily concerned with spatial planning and risk management. Network participation is typically homogenous, which limits temporal boundary spanning and constrains efforts toward more transformative adaptation. We argue that national legislation reinforces institutional path dependencies, steering municipal collaboration toward compliance-oriented, siloed approaches. The analysis highlights the need for more diverse and holistic forms of cooperation to overcome these structural limitations and support long-term, systemic adaptation in Arctic governance contexts.