what is uv light?

What is UV light?

It's important to understand what UV light is so that you understand what makes the sun so powerful and damaging to your skin if left unprotected. So here are the facts about UV light and the different types of rays the sun gives out.

UV Light - What is it?

The effects of UV light are invisible and unnoticeable, and small amounts of UV light is important to keep us healthy as we need it to produce Vitamin D but overexposure to the sun can be very damaging.

Ultraviolet light, UVA and UVB are frequently mentioned on sunscreen bottles and we know they're harmful to us but here's exactly what they are and why this is.

There are 3 different types of rays released by the sun

UV light is a type of electromagnetic radiation that causes our skin to become tanned but can also be damaging to our bodies if overexposed to it.


  • UVA has the longest wavelength of the different types of rays 
  • Accounts for 95% of the UV light that reaches the Earth 
  • UVA is most responsible for your skin getting darker when exposed to the sun as it damages the skin's DNA, causing your skin to darken  
  • UVA penetrates deep into the dermis of the skin contributing to the development of skin cancers due to DNA damage of the skin


  • Of the different types of rays UVB has a medium wavelength
  • Accounts for 5% of the UV light that reaches the Earth as most solar UVB is filtered out by the ozone layer so does not reach the Earth's surface
  • UVB only penetrates the outer layer of the skin and is responsible for early signs of aging such as wrinkles, loss of skin elasticity, and discoloured patches on the skin
  • UVB does not contribute to tanning but in fact is one of the causes of sun damage on the skin's surface


  • UVC is the most damaging type of wavelength and is also the shortest
  • The ozone layer filters out almost all of UVC light so it doesn't actually reach the Earth's surface, this is why sunscreen does not need to protect us against it
The many types of light

3000–800 NM

Infrared radiation (IR radiation) emits warmth. Although we cannot see its colour, we perceive it as the sun’s heat.
The many types of light

800-400 NM

The wavelength range of 400–800nm represents light that is visible to humans, which we see in all the colours of the rainbow.
The many types of light

400–320 NM

UVA rays are filtered to a small degree by the ozone layer. However, some rays reach the surface of the earth and can penetrate even the deeper skin layers.
The many types of light

320–290 NM

Some UVB rays are absorbed by the ozone layer, but the majority still reach the surface of the earth. Although the UVB rays only penetrate the epidermis, they can cause sun damage and DNA damage. That’s why it is very important to ensure you have sufficient protection from UVB rays.
The many types of light


UVC rays would be extremely dangerous for all forms of life if they actually reached the earth’s surface. Fortunately, they are absorbed completely by the ozone layer – even in regions where it is damaged. UVC protection is therefore not necessary.

The intensity of UV Light

When are you most exposed to UV light?

We recommend wearing sunscreen with a high SPF at all times to keep your skin protected against the sun and also as a way to help combat the signs of aging. Having said this, there are a number of factors that affect your level of UV light exposure, and it's important to have an understanding of this so that you can make sure you're giving yourself the best protection against sun overexposure.

UV Light is sometimes stronger, sometimes weaker

  • Daily: The intensity of UVB rays is linked to the position of the sun and changes over the course of the day. It can be up to 150 times stronger at midday than it is at 6 a.m. In general, you should avoid excessive sunbathing and not spend time in the sun at all between 11 a.m. and 3 p.m. in particular and it's important to wear sunscreen to protect against sun rays every day to prevent sun damage to your skin. Try the NIVEA SUN Protect & Refresh Cooling Sun Spray SPF 50.
  • Seasonal: The UV intensity varies depending on the season and is stronger in summer than in winter. The risks associated with the UV intensity also vary accordingly. The proportion of sun overexposure damage-causing UVB rays is higher in the summer months than in winter. Throughout the year, the proportion of UVA rays in sunlight is open to less strong fluctuations than is the case for UVB rays. The risks associated with UVA rays can certainly be estimated at a more constant level, which is why appropriate UVA protection is important, even for short periods of time in the sun.
  • Near the equator: Both the general UV light intensity and the proportion of UVB rays increase as you get closer to the equator – unlike UVA rays, in which the proportion is similarly high all over the world. Sun rays have less distance to travel to reach the Earth's surface when you're closer to the equator, so less UV light is filtered out by the ozone layer on it's journey. This is why it's really important to apply sunscreen especially when you go on holiday to these areas and apply sunscreen more often while away.
  • Clouds: Clouds generally only slightly affect the intensity of UV radiation, sufficient protection is also necessary on cloudy days.
  • Altitude: In Central Europe, the UVB intensity rises by 15–20% for every 1,000 metres above sea level. At an altitude of 3,000 metres, it lies at around 50%. The higher up you get the less distance the UV light has to travel before it reaches you, so when you're out hiking or on a skiing trip in the mountains need to make sure you use sufficient sun protection at all times.
  • Shade: Even though shade offers considerable protection against UV light, it does not completely shield us from it. A significant amount of light can be reflected off surfaces and objects, meaning that even areas that appear to be in the shade are reached by sunlight. We recommend protecting your skin from the sun even when in the shade.
    Water, sand, and especially snow reflect UV sun rays and increase their intensity on our skin, for snow this can actually double! That's why it's so important to wear a high SPF sunscreen when you're in these environments.


Find out what SPF really means here and discover how to use NIVEA sunscreen.

NIVEA & UV Light

All of the NIVEA Sun collection contains effective UVA and UVB filters to give you the very best protection against the sun and have been carefully created to suit everyone's individual needs: