Wondering if you should wear suncream all year round? It’s a good and important question, and one best answered by one of the leading figures in this field: Antony R Young, Emeritus Professor of Experimental Physiology at King’s College London, whose research interests include mechanisms of UV-induced skin damage.
“Suncream is designed to prevent sunburn, which is mainly caused by the UVB radiation wavelengths in sunlight,” says Young. The sun emits two types of ultraviolet (UV) that reach our skin: A and B. “The UVB content of sunlight depends on the height of the sun, so it varies with time of day, season and latitude. For instance, in winter in the UK, when the sun is low, there is virtually no UVB in sunlight so there is no need to wear suncream. However, the importance of wearing suncream increases as you approach the equator.”
When should you wear suncream?
Your best guide is to use the local UV index (UVI), which is a measure of the strength of the sun’s ability to cause sunburn, and is readily available on weather websites and apps. “Public health authorities advise using suncream when the UVI reaches three,” says Young.
As those of you like this very pasty-skinned writer only know too well, your chances of suffering sunburn are also dependent on your skin type. “This is an indicator of the amount of melanin in habitually sun protected skin and your ability to tan (i.e., produce new melanin),” says Young.
Melanin is a substance in your body that produces skin, eye and hair pigmentation. The more melanin you produce, the darker all three will be. How much melanin’s in your body depends on a few factors, including genetics and how much sun exposure your ancestors had. “The lighter your skin, the more easily you sunburn, so the more cautious you must be in the sun. Understandably, the main goal is to avoid sunburn, which is inflammation of the skin.”
Which is why if the sun’s out, you must arm yourself with more than a bucket and spade before hitting the beach. “If you plan to spend time in the sun without shade, it’s essential to apply suncream liberally and evenly on all exposed body surfaces,” says Young. “Which sun protection factor (SPF) you choose again comes down to many factors, but if you sunburn easily, you need an SPF of 50 when in sunny parts of the world.”
Pay attention to Young’s apply liberally advice. That’s because SPF is based on the assumption that suncream is applied at a thickness of 2 milligrammes per centimetres squared according to manufacturer’s instructions.
A 2018 study by Young revealed that when suncream is applied in atypical fashion, it provides just 40% of the protection you might expect based on the SPF. “An average sized woman on a beach holiday would need 100ml per day for three whole body applications.” With skin cancer rates at an all-time in the UK in 2024, it’s worth the spend.