What UV Index is Best for Tanning?

UV index
By Ellie Taylor 16th May 2022 Category: Advice
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Medically reviewed June 2023, by Dr Benedetta Brazzini for sk:n. Next review due June 2024.

What is the best UV index for tanning? 

Getting a sun tan requires exposure to ultraviolet (UV) radiation. But when is the best time to get a tan without burning? We take a look at the most commonly asked questions on tanning and the best ways to protect your skin against the harmful effects of UV rays.

What is the UV index?

The UV index (UVI) refers to the strength of ultraviolet rays at any given time and place. The intensity of UV rays varies throughout the year, depending on how close you are to the sun. For example, in December, the sun is closer to the Earth in the Southern Hemisphere than in the North, meaning that the level of ultraviolet radiation will also be higher.

In the early 90’s, Canadian scientists developed a UV index scale to help the public protect themselves from UV radiation.

UV index chart

The UVI values range from 0 to 11. The higher the value, the greater the risk for damaging the skin and eyes, and the quicker it takes for harm to occur. In extreme UV environments, it is recommended to limit the time outdoors as much as possible and stay inside between 10 AM – 4 PM.

If you do need to go out during times when the UVI is at its highest, be sure to wear protective clothing such as a long sleeved top, a wide brimmed hat and sunglasses.

The best place to find the UV index of your location on a given day is Google or your smartphone’s weather app.

When should I sunbathe?

Exposure to the sun’s UV rays can cause damage to the skin and can even lead to skin cancer – even when it’s not particularly hot outside, or it’s cloudy. Sun exposure and tanning can also cause premature ageing due to the effect of UV radiation on the skin’s collagen and melanin levels.

However, some exposure to the sun can be helpful for skin conditions such as acne, and it also provides vitamin D which allows the body to absorb calcium and phosphorus from food.

The National Institute for Health and Care Excellence (NICE) recommends at least 10 to 15 minutes of sun exposure (without sunscreen) daily between March and October, from 11 am to 3 pm. Darker skin tones actually need to spend more time in the sun than this to achieve the same benefit. For longer periods, it is important to wear broad spectrum sunscreen.


Why do we tan?

Exposure to UV radiation increases the pigment melanin in your skin. UVA radiation triggers the release of melanin within the skin itself, while UVB radiation stimulates your body to produce more melanin, resulting in a sun tan.

Both of these types of UV radiation are present in the sun’s rays. In order to get a suntan, the UV radiation needs to be high enough to affect the level of melanin in your skin, without burning.

Is there such thing as a healthy tan?

It’s worth noting that even just getting a tan is actually a sign of sun damage, so there is no real ‘best’ UV index for tanning. In its guidelines on sun exposure, the NHS says “the idea that there is such a thing as a healthy tan, is a myth.” But, if you want to avoid burning, don’t sit out for long periods of time without sunscreen between 10 AM and 3 PM during the summer months and seek shade whenever possible. Click here to read our guide on how to spot the signs of sun damage and skin cancer.


When is UV radiation at its highest?

UV radiation is generally highest between 10 AM and 3 PM, during the summer, on a cloudless day. Some countries broadcast a UV index for each day on the weather report. However, this does not mean that a scorching hot sunny day is the best day to get a tan.

On these days, depending on your skin, even short exposure can cause sunburn. If you wish to tan on these days, you should use a stronger sunscreen in order to give your skin some level of protection from UV radiation. Even when tanning on a less-bright day, sunscreen is essential.

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What areas of skin need the most protection from the sun?

When tanning, make sure you wear protect sensitive areas such as your eyes, lips and scalp. You might want to consider protective eyeglasses, lip balms that contain sunscreen and hair styling products with at least SPF 30 protection. Sunscreen in a spray bottle is great for getting coverage on hard-to-reach spots such as your scalp. You should apply sunscreen every 2 hours to ensure your skin benefits from continuous protection.


Can you reverse sun damage?

Some of the visible signs of sun damage to the skin can be reversed or at least improved with professional skin treatments. Here are some examples of sun damage, and the treatments designed to address them:

  • Pigmentation and dark spots: Pigmentation is caused by excess melanin production, a common side-effect of sun exposure and tanning. Treatments designed to exfoliate and strip away the surface layers of the skin, such as laser resurfacingmicrodermabrasion and skin peels, are effective at breaking down this excess melanin and a revealing a fresher, more even complexion.


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  • Fine lines: Tanning depletes the natural collagen present in your skin, causing it to become crepey, dry and wrinkled. Skin peels help to strip back dry, dull-looking skin, whilst also stimulating new cell turnover and collagen production. Microneedling is another great treatment for stimulating cell renewal and collagen production, as it harnesses your skin’s natural healing process, for plumper, smoother, younger-looking skin.
  • Deep-set wrinkles and frown lines: Over time, sun exposure and tanning can lead to deep-set, stubborn wrinkles that won’t seem to go away, no matter how well you look after your skin. Anti-ageing injectables and dermal fillers work to smooth these out, putting much-needed volume and structure back into the skin.
  • Thread veins: Thin, sun-damaged skin is more prone to visible capillaries, known as thread veins, or spider veins. The good news is they can be considerably reduced with targeted, professional laser treatments.

A great way to reverse the signs of ageing which can be caused by too much exposure to the sun is to have a treatment of Skin Peels, which exfoliate your skin and encourage it to refresh itself by creating fresh new skin cells, whilst stimulating the skin’s natural collagen production to help target the appearance of fine lines and wrinkles.

Worried about the effects of sun damage? Book a consultation at your nearest sk:n clinic here.

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