In many parts of the country, a change of seasons is accompanied by a change in daily weather. Warm sunny days may give way to frequent cloudiness as cooler air masses move in. It may be tempting to shelf your sunscreen on overcast days, but even when the sun is shaded by clouds, you need full-spectrum sun protection.
It’s easy to see that clouds block sunlight. It’s why overcast days seem drearier and feel cooler. But clouds are really only effective at blocking rays on the visible light spectrum. Clouds do little to filter ultraviolet radiation, the sun rays that penetrate and damage your skin.
There are three types of ultraviolet radiation from the sun, defined by wavelength:
UVA and UVB rays can both penetrate clouds. So, even on overcast days, these types of radiation are penetrating your skin, and when they do:
The vulnerable compounds are often the compounds that comprise your dermal matrix—collagen and elastin. When free radicals attach to these fibers, they deteriorate, resulting in a loss of tone and resilience in your skin. The result: photoaging—hyperpigmentation, fine lines, wrinkles and sagging skin.
Most damage to the dermal matrix cause by UV radiation is preventable…you simply have to apply sun protection every day, regardless of the weather.