The summer is in full swing, and anyone wanting to spend time outdoors should not only check the temperature but also be aware of the UV Index (UVI). This is an internationally standardized scale indicating how strong the sun’s ultraviolet (UV) radiation is at a specific time and place. How can one find out the current UV Index in their vicinity?
How to Determine the Current UV Index
The World Health Organization recommends the SunSmart Global UV app. This application is available for free on Android and iOS. Here are the download links:
The app provides weather data but primarily focuses on UV radiation details in your vicinity. A semicircular graphic indicates critical periods of the day regarding UV radiation. The app utilizes the general scale for the UV Index and offers forecasts for the coming days.
The Global UV app provides five-day UV and weather forecasts for any location, even small villages. It also advises the times when sunscreen is recommended and shows the UV Index at your chosen location. Additionally, the app offers tips on how to protect yourself during high UV levels and can alert you when sunscreen is advised at your selected spot.
When Should You Use Sunscreen?
The app informs users about sun intensity and relies on national and local data sources for UV information, such as the European Centre for Medium-Range Weather Forecasts. With the app’s information, you can adjust your behavior on days with high solar radiation. According to the data (source: WHO):
- 0 to 2: No risk, staying outdoors is safe.
- 3 to 7: Spend midday hours in the shade. Skin should be covered, and wearing a hat is advisable. Sunscreen is also recommended.
- 8 and above: Avoid outdoor activities during midday and do not skip wearing a shirt, sunglasses, sunscreen, or a hat.
Find more about effective sunscreens in our recommendations.
At What UV Index Will You Tan?
Data can also indicate when your skin may start to tan. However, tanning is not a harmless cosmetic effect; it is a protective reaction to UV damage. UV radiation causes damage to the DNA of skin cells (source: Skin Cancer Prevention).
- At a UV Index of about 3 to 5, noticeable tanning begins for sensitive skin.
- At UV 6+, this effect intensifies, but the risk of sunburn increases rapidly.
The Dermatological Prevention Association (ADP) warns against the dangers of intentional tanning:
A healthy tan does not exist. Pigmentation is a reaction to damage already inflicted by UV radiation and offers only limited protection against cancer-causing UV radiation. Thus, intentional tanning should not be pursued under the sun or in tanning beds.
When Should You Start Using Sunscreen?
Experts recommend consistently using sunscreen with at least SPF 30 starting from a UV Index of 3. This is particularly important during 11 AM to 4 PM, when UV exposure is the highest. Reapply at least every two hours or immediately after swimming or sweating.
What Is Behind the UV Index?
The index was developed by the World Health Organization (WHO), the World Meteorological Organization (WMO), and other health authorities. This value serves as a guide to the risk of skin damage, including sunburn, skin aging, and skin cancer, as well as eye damage from UV rays. The scale ranges from 0 (no UV exposure) to 11+ (extreme UV exposure).
Index values start from zero upwards—the higher the UVI, the greater the risk of skin and eye damage, and the shorter the time span until damage occurs.
Finding the UV Index Without an App
If you prefer not to install an additional app, you can view the UV Index for certain locations in Germany on a map provided by the Federal Office for Radiation Protection.
The data comes from solar UV measurement networks, which collect values from 43 locations in Germany. Click on a point on the map to learn the current UVI for that measurement site.
Additional Apps Featuring UV Index
You can also find the current UV Index in most popular weather apps. You might need to scroll down in the daily data or open a detailed view. Here are some free alternatives to the WHO recommendation:
UVI Mate Also Accounts for Vitamin D3
UVI Mate not only displays the UV Index but also tells you how long you can safely stay in the sun without burning, based on your skin type and other parameters. It also indicates how long you should sunbathe to replenish your Vitamin D3 stores. Like UVLens, it features an alert function reminding you when to reapply sunscreen. Currently, UVI Mate is only available for Android:
UV Index Forecast with UVLens
UVLens, like UV-Check, shows you the UV Index at your current location and includes a forecast for both the current and next day. Considering various parameters such as skin type, it shows how long you can currently stay in the sun without risk of sunburn. It can also take into account sunscreen application and remind you when to reapply.
Stay informed and enjoy your summer safely by keeping an eye on the UV Index!
