UV radiation is a high- energy part of the electromagnetic spectrum emitted from the sun and is responsible for causing skin damage, premature ageing and skin cancer.
UV radiation can’t be seen and, unlike infrared radiation (heat), we cannot feel it either. UV levels are not related to air temperature and high levels of UV radiation also occur on cool days. Therefore, weather should not be used to determine the need for sun protection.
UV radiation levels can be categorised using the UV Index which is divided into low (1–2), moderate (3–5), high (6–7), very high (8– 10) and extreme (11).
Once the UV Index reaches a moderate level, it is strong enough to cause damage to the skin and the higher the Index, the less time it takes for skin damage to occur. Skin should be protected in five ways (Slip, Slop, Slap, Seek, Slide) whenever the UV Index is 3 and above.
UV levels change throughout the day and reach the maximum level around midday when the sun is directly overhead. Similarly, UV radiation is strongest during the months that the sun is directly overhead.
In South Australia, this is from August to May. During this time, and UV levels across the day range from moderate to extreme so sun protection is required.
The Bureau of Meteorology predicts UV levels with the weather forecast every day and provides us with local daily sun protection times (for example 9.30 am–3.30 pm). The sun protection times tell us when UV is predicted to be 3 and above and therefore when sun protection is required. It is a useful tool for anyone planning outdoor activities. UV levels and sun protection times can be accessed by downloading the free SunSmart app or by adding the SunSmart widget to your website.
Want to know where this information comes from? Click here.
This website page was last reviewed and updated March 2019.