As a dermatologist, I often see patients who are surprised to find out they have a sunburn, despite being outside on a cold winter day or on a cloudy day. Many people believe that the sun's harmful rays are blocked by clouds or that they are only at risk of sun damage during the summer months. However, this is far from the truth. Firstly, it is important to understand that the sun emits ultraviolet (UV) radiation, which is divided into UVA and UVB rays. These rays are present year-round, regardless of the weather or season. UVB rays are responsible for causing sunburns, while UVA rays penetrate deeper into the skin and cause premature aging and skin damage. While clouds may provide some protection from UVB rays, they do not offer complete protection. Clouds can reduce the amount of UV radiation that reaches the earth's surface, but they do not block all of it. In fact, up to 80% of UV rays can still penetrate through clouds, which means that even on a cloudy day, you can still ...
Patient information resource on dermatological conditions and skin care