The UV index (UVI) is a measure of the highest sunburn effective irradiance, which is caused by the sun during the day. The UVI depends primarily on the position of the sun as well as on the clouds and the altitude of a place. Light clouds hardly reduce the UVI. However, special cloud forms may also lead to a short-term increase of the UVI. Even snow, water and bright sand surfaces can cause exposure to radiation higher than the predicted maximum UVI. The reason is that the UV radiation is reflected to light or reflective surfaces.
It is internationally established that the UVI should be quoted in whole numbers from 1 to 10. Even higher values are designated by 11+. Within this scale following evaluation standards and protection recommendations apply:
|UV index||rating||protective measures|
|0-2||low||No protection needed|
|3-5||moderate||Protection Required (Shadow, T-shirt, sunscreen, hat)|
|6-7||high||Protection Required (Shadow, T-shirt, sunscreen, hat)|
|8-10||Very High||urgent protection required(avoid staying outdoors if possible)|
|11+||Extreme||urgent protection required (avoid staying outdoors if possible)|
The UVI values for Berlin were provided by an institution 60km southeast of the city. The company sglux SolGel Technologies GmbH wanted to change this situation and since 2014 operates Berlin's first UV index observation station on the roof of the company's building. The current values of the station will be redirected to the company's website and on the website of Advanced UV for Life.
The following charts show the current daily values and the values of the previous day as part of the internationally agreed scale of 1-10.