NEW!IEC 60721-2-4:2018 is available as IEC 60721-2-4:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 60721-2-4:2018 presents a broad division into types of solar radiation areas. It is intended to be used as part of the background material when selecting appropriate severities of solar radiation for product applications. All types of geographical areas are covered, except areas with altitudes above 5 000 m. This second edition cancels and replaces the first edition published in 1987 and Amendment 1:1988. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - Figures updated including the addition of global irradiation information - Format updated.