This document specifies the conditions to take into consideration when selecting the type of natural weathering and the natural weathering procedure to determine the resistance of coatings or coating systems (direct weathering or weathering behind window glass). Natural weathering is used to determine the resistance of coatings or coating systems (denoted in this document by coatings) to the sun's radiation and the atmosphere. This document does not take into account special atmospheric influences, e.g. industrial pollution.