Soak up the sun carefully. Light and heat are good, but the skin needs adequate UV protection. © Getty Images
If you are in the sun, you should protect your skin. To what extent, the UV index is a good guide. Stiftung Warentest explains what it means.
The higher the UV index, the higher the risk of sunburn
When sun-seekers raise their faces towards the sky, they should not forget the risks of ultraviolet radiation: sunburn, premature wrinkling and skin aging – and in the long term skin cancer. But how dangerous is the sun right now or tomorrow when a long trip to the bathing lake is planned? Anyone can consult the UV Index (UVI) for this. It applies to all skin types and is a measure of the daily peak value of the sun’s UV radiation that causes sunburn. The UV index has the same meaning worldwide and was introduced by recognized institutions, including the World Health Organization (WHO). The higher the UVI, the faster unprotected skin can be damaged – for example by sunburn.
What affects the UV value
The level of the UV index is influenced by the position of the sun and the ozone level in the atmosphere. Its calculation also includes how cloudy it is at the moment and how high the current location is above sea level. According to the German Weather Service, experience has shown that the UV index in Germany reaches values of up to 8, in extreme cases 9 and in the higher altitudes of the Alps also up to 10. Those who travel to the tropics and subtropics must reckon with values of 14 to 16. Values above 17 are also possible at particularly high altitudes, such as in the Andes. However, values that go far beyond this on the open-ended scale are considered rather unlikely in areas inhabited by people.
Proper protection is possible thanks to daily forecasts
The German Weather Service, in cooperation with the Federal Office for Radiation Protection (BfS), predicts the UVI values for various regions of Germany on a daily basis. The values are determined across the board at 7 km intervals. For this purpose, the UV radiation incident on the ground is measured continuously from sunrise to sunset at many different measuring network stations in Germany. You can find the current UVI values on the Internet – on the websites of the German Weather Service or des Federal Office for Radiation Protection. In addition, the BfS publishes every Monday, Wednesday and Friday from April to September 3-day UV forecasts for the ten most important forecast areas in Germany – from the coast to the Alps. In the months from October to March, only maximum monthly UV index values are given.
From UVI 3 you should protect yourself
© Federal Office for Radiation Protection
According to the WHO, protective measures are necessary from UV index 3: Everyone should go into the shade in the midday hours and otherwise protect themselves with appropriate clothing, a hat and sunglasses. Uncovered skin should be sunscreened. The Federal Office for Radiation Protection (BfS) recommends a high sun protection factor of at least 30 for children and at least 20 for adults. But if you plan to stay in the sun for a long time, you should take a product with an even higher factor to be on the safe side, around 50 or 50+. Because the higher the SPF number, the longer the protection period.
Tests and information about sunscreens
Stiftung Warentest regularly examines sunscreens:
Test sunscreen for adults
Test sun protection for children.
You can also protect the facial skin in everyday life with a good day cream with UV protection. You can read more information about sunscreens in our FAQ sunscreens.
This is how you protect yourself from too much UV radiation
If you are planning an extended stay outdoors, such as a long hike, bike ride, or day at the beach:
- Find out what the current predicted UV index is.
- Prepare yourself for the right UV protection at home: pack sunscreen and a hat.
- If necessary, plan a break in the sun at lunchtime – outside in the shade or just inside.
- Apply cream regularly and generously.