Cold temperatures and cloudy skies do not mean ultraviolet radiation disappears, which is why skin protection remains important throughout winter in Gauteng. UVA and UVB rays are present throughout the year, although their intensity changes with the season, and people who spend time outdoors or close to windows may still receive ultraviolet exposure. However, sunscreen is generally not necessary for people spending the entire day indoors away from direct sunlight, according to guidance from the Cancer Council Australia.