In winter, it is easy to think that you can skip sunscreen because the sunlight is weak. However, in reality, even in the middle of winter, UV rays penetrate deep into the skin, causing pigmentation, loss of elasticity, and worsening dryness. Especially, UV rays reflected by snow and ice are stronger than you might think, and even indoors, UVA can pass through windows and age the skin. Let's explore the reasons why you must apply sunscreen even in winter.
UVA Remains the Same in Winter... Direct Impact on Skin Elasticity, Wrinkles
While UVB decreases in winter, UVA reaches the skin almost the same as before. UVA penetrates beyond the epidermis into the dermis, damaging collagen and elastin, accelerating wrinkles and sagging skin. Even if the sunlight seems weak, cumulative damage can occur after just 10-20 minutes outdoors. In high-altitude environments like ski resorts or hiking, the intensity of UVA can actually increase.
Reflected Light from Snow and Ice Doubles UV Rays... Ski Resorts and Hiking are 'Unprotected Exposure'
In winter, snow and ice can reflect UV rays by 30-80%. Especially at ski resorts, both direct UV rays and ground-reflected UV rays can lead to greater skin damage than in summer. The reason pigmentation around the cheekbones and nose becomes more pronounced in winter is due to this reflected light. Even on cloudy days, the reflected light does not significantly decrease, making it easy to let your guard down.
Dryness from Heating Plus UV Rays... 'Internal Dryness + Pigmentation' Occurs
Skin that has become dry due to heating has a weakened barrier, allowing moisture to escape easily. When UV rays hit in this state, melanin production becomes more active, worsening dark spots and blemishes. The combination of hot air and UV rays can cause moisture within the skin to evaporate, leading to roughness and redness. Sunscreen not only blocks UV rays but also protects the skin from wind and dust.
UVA Passes Through Windows Even Indoors... Causes 'Office Dark Spots'
UVA has a long wavelength and passes through windows easily. In winter, we spend more time indoors, but exposure to UVA from windows accumulates photoaging. Just the habit of sitting by a window while driving, at the office, or in a café can increase pigmentation. This is why sunscreen is necessary even during indoor activities in winter due to UVA.
80-90% Reaches Even on Cloudy Days... Winter Carelessness Leads to Pigmentation
On cloudy days, it may feel like UV rays are weak, but clouds do not completely block UV rays. In fact, 70-90% of UV rays reach the skin, and with repeated exposure, pigmentation gradually builds up. Short outings like commuting, walking, or moving during lunch accumulate, making dark spots and blemishes appear more pronounced by spring. A little carelessness in winter leads to changes in pigmentation.
