July 13, 2025, 2:28 pm | Read time: 4 minutes
For many people, a glowing tan is simply part of the summer months. However, the cost of bronzed skin can be high—especially if you neglect UV protection while sunbathing. UV warning apps can help you stay safe. Learn more about this at TECHBOOK.
According to the Federal Statistical Office, the number of inpatient skin cancer treatments has increased by 87.5% over the past 20 years. This is certainly also due to the fact that more preventive examinations are conducted today. However, deaths related to skin cancer have also risen by an alarming 60.8% in the same period. This trend highlights the importance of paying more attention to sun protection in everyday life. UV warning apps can help with this.
Overview
What Can UV Warning Apps Do?
UV warning apps commonly display the current UV index for a specific location—updated hourly or in real-time, depending on the app. Generally, these apps source their information from the internet, using live weather data from official weather services, as smartphones and smartwatches typically do not have their own UV sensors. The collected data is matched with the device’s GPS data to determine the local UV level as accurately as possible. However, some apps require manual location input, which can affect accuracy.
There are also specialized wearables with their own sensors, such as the UV tracker Sun-a-Wear. These devices measure actual UV exposure directly and send a warning to the connected app once the personal threshold is reached. For a time, there was a UV patch from the cosmetics company L’Oréal, but production has since been discontinued.
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Available UV Warning Apps
Most UV warning apps operate on a similar principle. Some calculate an individual protection time based on skin type, duration of exposure, and sun protection factor, while others are more general. Here is an overview of the common options.
SunSmart Global UV – for Android and iOS, free
First on the list is the SunSmart Global UV app—a joint initiative of the World Health Organization (WHO) and international partners, using their data. Users can be located via GPS or manually enter worldwide locations to get UV exposure information at their travel destination. The app also provides sun protection recommendations.
Read also: 5 Apps to Survive the Hot Summer Days
UV Lens – for Android and iOS, free
This app uses various global weather services, as stated on its website, along with algorithms developed by the team. It offers a UV index and the option to set a sunscreen reminder. The app also includes a skin type analysis feature.
SunWise UV Index – for Android and iOS, free
This app is from the U.S. Environmental Protection Agency (EPA) and provides daily forecasts of UV radiation levels on a scale from 1 (low) to 11+ (extreme). According to the EPA website, it helps plan outdoor activities and supports informed decisions regarding sun exposure. The app also shows how the UV index changes throughout the day.
Wolfram Sun Exposure Reference App – iOS only, about 1.99 euros
This app provides, in addition to the standard features of a classic weather app including sunrise times, UV forecasts for the current location and many other places worldwide, with interactive UV maps and data for five days in advance. The Wolfram Sun Exposure Reference App also aims to predict how long users can stay in the sun—with a recommended UV protection level—before a sunburn is likely.
Sunscreen SPF Timer – iOS only, about 3.99 euros
The most expensive of the common UV warning apps, but possibly the most reliable? Like most others, it shows the current UV index at the location and calculates individual protection time based on personal skin type, location, and sun protection factor. It also uses an alarm to remind users to reapply sunscreen. Depending on the environment (beach, city), widgets allow quick access to UV and weather data without opening the app.
SunTanApp – Android only, free
This app also provides the UV index and recommendations for the appropriate sun protection factor (SPF). It also indicates how long users can stay in the sun without burning. The app allows users to plan breaks from UV exposure, such as during mountain hikes or at the beach. Users are categorized into skin types based on the official Fitzpatrick scale. With continuously collected global weather data, the app aims to provide particularly accurate information.