Protection from UV radiation: Why Sun safety matters all year round

Many people associate sun protection with hot summer days and holidays abroad. However, exposure to ultraviolet (UV) radiation occurs throughout the year, even during winter and on cloudy days. Protecting your skin from UV radiation is an important year-round health measure that can help prevent sunburn, premature skin ageing, and skin cancer (AAD, 2021; WHO, 2024, 2025).

UV radiation can penetrate cloud cover and fog, meaning that skin damage can occur even when the sun is not visible. According to the NHS, it is possible to get sunburned in the UK on cloudy days because UV rays pass through clouds (NHS, 2026). Similarly, the World Health Organization (WHO) reports that up to 80% of the sun's ultraviolet rays can penetrate clouds and fog (WHO, 2025), contributing to skin damage during winter months (Skin Cancer Foundation, 2026).

While UVB radiation, the primary cause of sunburn, is strongest during summer, it can damage the skin all year round. UVA radiation, which contributes to tanning, wrinkles, and other signs of premature skin ageing, remains relatively constant throughout the year and can even penetrate glass (Skin Cancer Foundation, 2026).

As temperatures drop, many people become less vigilant about sun protection. However, winter conditions can significantly increase UV exposure. Clear winter skies allow UV radiation to reach the earth's surface, while reflective surfaces such as snow can intensify exposure (AAD, 2021).

Snow is particularly reflective and can bounce back as much as 80–90% of incoming UV radiation, effectively exposing the skin to UV rays from both above and below (Skin Cancer Foundation, 2026; WHO, 2024). This makes winter sports enthusiasts especially vulnerable.

UV exposure can also be intensified by other reflective surfaces such as water, sandy beaches, and light-coloured buildings. According to the WHO, white facades can reflect approximately 20% of UV radiation, while snow can reflect up to 90% (WHO, 2024).

Overexposure to UV radiation is the primary environmental cause of skin damage and is associated with harmful effects on the skin, or eyes (WHO, 2024, 2025). Sunburn is one of the most immediate consequences, but repeated UV exposure can have long-lasting effects.

Skin cancer rates have increased significantly over recent decades, and this trend is strongly linked to occupational and recreational UV exposure. Importantly, WHO estimates that up to four out of five cases of skin cancer could be prevented through proper sun protection measures (WHO, 2024, 2025).

Tanning is often perceived as a sign of health or attractiveness, but this perception is misleading. A tan is actually a visible sign of skin damage and the skin's attempt to protect itself from further UV exposure. There is no safe or healthy way to obtain a tan, and a tan does not protect the skin from the harmful effects of the sun (NHS, 2026; WHO, 2025).

Protecting the skin from UV radiation involves a combination of protective behaviours. The American Academy of Dermatology recommends seeking shade, wearing sun-protective clothing, and using sunscreen on all exposed skin throughout the year (AAD, 2021).

Particular care should be taken during periods of significant sun exposure, especially between spring and early autumn when UV levels are generally highest. However, year-round protection may be necessary in tropical regions and other areas with high UV indices (WHO, 2024).

Individuals should also take precautions during winter outdoor activities and prolonged exposure near highly reflective surfaces (Skin Cancer Foundation, 2026; WHO, 2024).

Sunscreen is an important component of sun protection but should not be viewed as a means of extending time spent outdoors. While sunscreen can delay the onset of sunburn, it cannot completely block UV radiation (EC, 2007).

Experts recommend using a broad-spectrum sunscreen that protects against both UVA and UVB radiation, with a minimum SPF of 30 (AAD, 2021; WHO, 2024, 2025). In the UK, sunscreen should also provide at least 4-star UVA protection (NHS, 2026).

To achieve the level of protection stated on the label, sunscreen should be applied generously and evenly to all exposed skin 20–30 minutes before going outdoors. Areas often overlooked, such as the ears, nose, forehead, neck, hairline, and around the eyes, require special attention (CDC, 2026; Skin Cancer Foundation, 2026).

Research has shown that many people apply too little sunscreen and therefore receive substantially less protection than expected. WHO recommends approximately 35 ml of sunscreen - or roughly three to four heaped tablespoons - for full-body coverage in adults (WHO, 2024). Sunscreen should be reapplied every two hours and after swimming, bathing, or excessive sweating (CDC, 2026; WHO, 2024).

It is also important to distinguish sunscreens from after-sun products. After-sun lotions may moisturise or soothe the skin but do not provide UV protection or repair UV-induced DNA damage (WHO, 2024).

Vitamin D is produced naturally in the skin when it is exposed to ultraviolet B (UVB) rays from sunlight. The process is highly efficient, and for most healthy people, only short periods of sun exposure during spring and summer are needed to maintain adequate vitamin D levels. Regular outdoor activities, such as a daily walk or spending time outside, are usually sufficient, and prolonged sun exposure is not necessary. In fact, vitamin D production reaches a maximum after a relatively short time in the sun, while continued exposure only increases the risk of skin damage and skin cancer. Therefore, it is important to enjoy the benefits of sunlight while avoiding sunburn and excessive UV exposure. Maintaining this balance helps support healthy vitamin D levels without compromising skin health (NHS, 2026; WHO, 2025).

UV radiation is a year-round health concern, not a seasonal one. When spending time outdoors on a cloudy day, UV exposure can still damage the skin. Consistent sun-protection practices—including seeking shade, wearing protective clothing, and using broad-spectrum SPF 30 or higher sunscreen—can substantially reduce the risk of sunburn, premature skin ageing, and skin cancer (AAD, 2021; WHO, 2024, 2025). Maintaining these habits throughout every season is one of the most effective ways to protect long-term skin health.

1. AAD. (2021). Why you need sun protection in the winter. In. Accessed on American Academy of Dermatology Association webpage on 2 July 2026: https://www.aad.org/public/everyday-care/sun-protection/shade-clothing-sunscreen/cold-weather.
2. CDC. (2026). Sun Safety Facts. In. Accessed from the US Centers for Disease Control and Prevention webpage on 2 July 2026: https://www.cdc.gov/skin-cancer/sun-safety/index.html.
3. EC. (2007). Sunscreen products: What matters? In. Accessed from European Commission webpage on 2 July 2026: https://ec.europa.eu/commission/presscorner/detail/es/memo_07_282.
4. NHS. (2026). Sunscreen and sun safety. In: Accessed on 2Jul2026 from: https://www.nhs.uk/live-well/seasonal-health/sunscreen-and-sun-safety/.
5. Skin Cancer Foundation. (2026). The Skin Cancer Foundation Shares Winter Sun Protection Tips. What to know about protecting your skin during colder months. In. Accessed on 2 July 2026 from: https://www.skincancer.org/press/the-skin-cancer-foundation-shares-winter-sun-protection-tips/.
6. WHO. (2024). Radiation: Protecting against skin cancer. In: Accessed on 2 Jul 2026 from: https://www.who.int/news-room/questions-and-answers/item/radiation-protecting-against-skin-cancer.
7. WHO. (2025). Fact Sheet; European Code Against Cancer, 5th Edition. 14 ways you can help prevent cancer. In: Accessed on 2 July 2026 from: https://cancer-code-europe.iarc.who.int/wp-content/uploads/2026/03/8-european-code-against-cancer-sun-protection-factsheet.pdf.