The development of power system models relies on large data sets, the quality, and openness of which determine the models' accuracy and efficacy. There are numerous data sources publicly available, for the Nordic region though spread across diverse repositories and organised in different schemas. Their combination and cross-validation is a tedious process, usually undertaken by researchers or practitioners, in an ad hoc fashion. This paper identifies, compares, and validates various publicly available power systems data sets, pertaining to the Nordic region. Their quality, level of detail, granularity, and similar characteristics are highlighted, while the challenges of data warehousing procedures are addressed, for the purpose to be used in realistic power systems-related case studies.