Purpose: Little is known about children sleeping outdoors in a northern winter climate, although it is a common practice in northern countries. The article describes the cultural meaning of this child care practice from the viewpoint of mothers. Design: Explorative descriptive study design was adopted and unstructured interviews were processed by qualitative content analysis. Participants: Twenty-one mothers of families in northern Finland participated. Results: Family, cultural outdoor sleeping practice and northern winter environment constituted compatibility, which consisted of four generic categories: strengthening family well-being through outdoor sleeping, taking notice of security perspectives, adaptation to the northern winter environment, and cultural knowledge-building processes. Conclusions: Family well-being was strengthened through outdoor sleeping of children when all security perspectives were first taken into account. Families were adapted to the northern winter environment and cultural knowledge was built. A fit was found between families, cultural child care practice, and northern winter environment constituting a coherent whole.