For Sweden, our general recommendation is to use sun protection from from March to October. The reason we only recommend this period is because the UV index is low (0-2) during the darkest months, November to February, when it is safe to stay out in the sun all day without sun protection. The UV index is a measure of the strength of the sun's harmful radiation. A high UV index means you should protect yourself from the sun to reduce the risk of damage and in Sweden the UV index ranges from 0-8 and is highest in the middle of the day during the summer months. However, it is important to remember to use sun protection if you go on a skiing holiday, even in the darkest months, when the sun's rays are reflected by the snow.