Friends at the beach in the summer
Body & Soul
28.05.2026 Christin Müller 1415

At what UV index should I stop going out in the sun?

Wouldn't it be nice to just enjoy the sun without having to worry about protection? The UV Index is here to help: a handy number that tells you just how intense the current sun's rays really are.

​​​​​​​Text: Patrizia Lehmkuhl, Edited by: Christin Müller 

Summary: Key Points at a Glance 

The UV Index is your free, daily-updated early warning system for sunburn, acute skin damage, and long-term risks such as skin cancer. You should consistently use sunscreen whenever the index reaches a value of 3 or higher. By knowing when protection is necessary, you can plan your outdoor activities wisely and avoid unnecessary risks. 

Read more in this article:

What is the UV index? 

UV stands for ultraviolet radiation. The UV Index (UVI) summarizes the intensity of UV radiation at a given location in an easy-to-understand number and indicates how quickly you are at risk of getting sunburned. The higher the number, the greater the risk of sunburn, skin aging, eye damage, and skin cancer. 

What is today's UV index?

Would you like to know what the daily UV index is in your area? The nationwide solar UV monitoring network measures the amount of UV radiation reaching the ground at over 40 locations across the country. You can find the latest measurement data on the BfS website.

What factors influence the UV index? 

Various factors determine the current UV index: 

  • Sun's altitude: The higher the sun is in the sky, the stronger the UV radiation.
  • Ozone and airborne particles: Higher levels of ozone and aerosols reduce radiation; lower levels result in higher readings.
  • Note: Water , sand, snow, or light-colored facades can increase the strain.
  • Cloud cover: Reduces UV radiation but does not provide complete protection—UV rays can still penetrate clouds.

Tip: You can find out the exact value by checking many weather services or using a UV index card. 

How do you use the UV index in practice? 

The UV index is not just an abstract number; it helps people take specific protective measures. The WHO has clearly defined this: 


Source: WHO, Graphic: pme Familienservice

Even brief exposure to the midday sun can otherwise lead to painful redness and blistering—and, over the long term, also increase the risk of skin cancer and eye damage.

Sunscreen SPF: What You Need to Know 

The sun protection factor (SPF) on sunscreen indicates how much longer you can extend your natural protection time after applying the product without getting sunburned. The Federal Office for Radiation Protection recommends: 

  • When the UV index reaches 3 or higher: Sun protection for everyone! 
  • Children: SPF 30 or higher 
  • Adults: SPF 15 or higher 

Even more important than choosing the right SPF is how you apply it: 

  • Amount: About 5–6 tablespoons for the whole body. 
  • Reapply sunscreen: Every 2 hours, as well as after swimming or drying off. 

Your skin type is key: Very fair skin can burn after just a few minutes. Remember: It’s important to apply sunscreen consistently and to supplement this with protective clothing and staying in the shade!

Which sunscreen is right for me?

Not sure which sunscreen is right for you or how to best protect your skin from the sun? In our in-depth article, you’ll learn what matters most when it comes to proper sun protection. 

 

Myths About the Sun and Sun Protection – Debunked 

“It’s cloudy, so I’m safe.” – Wrong. Clouds reduce UV radiation, but they don’t block it completely. 

“Tanned skin doesn’t need protection.” – False. Darker skin offers some additional natural protection, but not complete protection. 

“Sunscreen alone is enough.” – Wrong. The best approach is a combination of sunscreen, clothing, shade, and adjusting the amount of time spent outdoors. 

“Using sunscreen leads to vitamin D deficiency.” – False. There is no scientific evidence to support this claim. 

Practical tips for sun protection in your daily life 

  • Use UV information (from weather services, UV index charts) to adjust your daily plans—such as what to wear, how long to stay outside, and when to engage in outdoor activities. Handy tip: An UV index chart shows you the exact UV index value for your current location. 
  • When the UV index is high: Try to schedule outdoor activities outside of the hours between 11 a.m. and 3 p.m. 
  • Extra protection is necessary, especially in conditions with strong glare (water, sand, snow, bright surroundings, or in the mountains). 
  • Take special care to protect children—their skin is very sensitive. 

Bottom line: The UV index protects your skin 

The UV Index is your reliable guide for sunny days. Experts recommend consistent sun protection starting at a UVI of 3: apply plenty of sunscreen, reapply it regularly, seek shade, and keep a close eye on children.

Don't be fooled by myths: even clouds and pre-tanned skin don't give you a free pass. Use the UV index to plan your day, avoid the intense midday sun, and enjoy the summer worry-free. 

In short: By checking the UV index, you can protect yourself and others in a smart way and enjoy the sun without worry. 

FAQ: Frequently Asked Questions About the UV Index & Sun Protection 

At what UV index should I stop going out in the sun?

It doesn’t necessarily mean “no longer,” but once the UV index reaches 8 (very high), you should avoid direct sunlight, seek out shaded areas, and take extra precautions (high SPF, protective clothing, a sun hat, and sunglasses). Once the UV index reaches 3, you should consistently use sunscreen.

Do I need sunscreen when it's cloudy?

Yes. Clouds block some UV rays but do not provide complete protection. Even on cloudy days, UV radiation can still cause skin damage—sun protection is recommended, especially when the UV index is 3 or higher.

What does the sun protection factor (SPF) on sunscreen mean?

The SPF indicates how much longer you can stay in the sun after applying sunscreen without getting sunburned, compared to your natural protection time. For example, SPF 30 theoretically extends your natural protection time by a factor of 30.

What SPF ratings are recommended?

From UVI 3: Sunscreen for everyone. Recommended: SPF 30 or higher for children; SPF 15 or higher for adults. In cases of high intensity (UVI ≥6), experts recommend SPF 30–50+ depending on skin type and duration of exposure.

How much sunscreen should I apply?

Guideline: Approximately 2 mg/cm² of skin—which is equivalent to about 5–6 level tablespoons for the entire body. In practice: Apply generously; do not use just a few sparing dabs.

How often do I need to reapply the sunscreen?

At least every 2 hours, as well as immediately after swimming, heavy sweating, or drying off.

Is sunscreen alone enough?

No. The best protection comes from a combination of sunscreen, protective clothing (UV-protective clothing), shade, a sun hat, and sunglasses, as well as planning your schedule (avoiding the midday hours).

What is the difference between UVA and UVB?

In short: UVA rays penetrate deeper and accelerate skin aging; UVB rays cause sunburn and are a major factor in skin cancer risk. Both are harmful and should be minimized.

What special considerations apply to children and babies?

Babies (under 1 year old): Avoid direct sunlight; keep them in the shade and dress them in protective clothing. For children: Use SPF 30 or higher, reapply frequently, and take extra precautions between 11 a.m. and 3 p.m. and in reflective environments (water, sand, snow).

How can I use the UV index to help me plan my day?

Check the UV index in the morning or throughout the day (weather services, BfS/DWD). Plan activities for the morning or later in the day, and choose appropriate protective measures based on the UVI level (e.g., UVI 3–5 → SPF 30, shade; UVI 6–7 → SPF 30–50, short stays; UVI ≥8 → stay in the shade, protective clothing, high SPF).

Sources & Recommended Reading 




 

zero Interview Longevity Growing old healthily

to see is Dr. Kati Ernst
Body & Soul
24.09.2025 Isabel Hempel 7444

Growing old healthily: Insights on longevity by Dr. Kati Ernst

Dr. Kati Ernst is one of the leading experts in the field of longevity research with a special focus on nutrition and sports science. She is passionately committed to helping people not only to live longer, but above all to live healthier lives.
In this interview, Kati Ernst explains exactly what longevity means, which scientific advances are currently particularly promising and how lifestyle and social relationships make a decisive contribution to quality of life. She gives valuable personal tips for a fulfilled and long life.

"Lifestyle influences over 80 percent of our longevity"

1. what does "longevity" mean to you and why is it such an important topic in today's world?

Dr. Kati Ernst: Longevity as a trend describes the effort to live as long a healthy life as possible, i.e. to minimize the span between the end of life and the end of a healthy life. Nowadays, many people live with multiple chronic diseases in the last ten years of their lives. The first priority is to prevent these.

And then it's all about postponing the end of a healthy life as far back as possible. This trend is certainly a result of the coronavirus pandemic, which has brought the mega topic of health back into focus worldwide. 

2. which scientific advances do you see as the most promising in longevity research?

Dr. Kati Ernst: As Longevity is about a long, healthy life, it naturally includes an incredible number of areas of research and life. This ranges from findings in the field of nutritional science and sports medicine to pharmacological developments. It is therefore difficult to pick out just one area.

One study that I find particularly exciting is the so-called TAME study from the USA. This study is investigating how the diabetic drug metformin could potentially prolong the lives of non-diabetics. As metformin is no longer patented, it is particularly cheap, and if it could actually help non-diabetics to live longer, that would be a big step forward for broad sections of society. 

3. How do lifestyle and diet influence lifespan and quality of life? Are there any specific habits you would recommend?

Dr. Kati Ernst: Our lifestyle actually determines over 80 percent of our longevity, and thus lifestyle changes should be the focus of any efforts in this area. This primarily involves four areas: nutrition, exercise and movement, recovery and sleep, and emotional health. These four areas are equally important and should all be part of a holistic longevity lifestyle. 

4. can everyone age more healthily?

Dr. Kati Ernst: There's nothing wrong with that at first. Especially as most major lifestyle adjustments do not involve major financial expenditure.

"Social relationships and health are key to happiness"

5 What role do social relationships and communities play in longevity? How can we strengthen these aspects?

Dr. Kati Ernst: A Harvard study spanning eight decades has shown that social relationships and health are the keys to a happy life. Therefore, relationships are a core component of the emotional health pillar, which is a cornerstone of the longevity lifestyle.

Nurturing human interactions should be just as important as adjusting your diet or creating an exercise program. For some people, the focus will be on welcoming new people into their lives, for example by joining a club.

For others, it will be more about deepening existing relationships, for example by meeting colleagues you like outside of working hours. 

6. what is your personal advice for people who are striving for a long and fulfilling life?

Dr. Kati Ernst: I think an important first step is to take some time to think about why you want to have a long and fulfilling life. Thinking intensively about these thoughts gives the whole thing a greater sense of purpose, which helps to implement life adjustments more successfully.

And then, of course, it's about looking at the areas where you have the biggest construction sites. That's where you should start. For some, it will be about making a successful dietary change, for others it will be about integrating sport into their lives in the first place. A third person will finally prioritize their own sleep. Where you start is always very individual.

Lectures, workshops, podcasts that promote our resilience

The Lost in Space?" initiative invites you with openness and curiosity to explore new paths that give us support and direction in these intense times. Because finding solutions requires strength - and is only possible together. 

With inspiring talks, interactive workshops, podcasts and blog articles, we create space to find inner clarity and strength and remain resilient. Join us on an exciting journey to new perspectives and opportunities!

Patrizia Lehmkuhl

Educational Consultant and Health Manager

 

Contact:

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