Are there UV rays when there is fog or rain?

Answer 1

Yes, the degree to which you are burned is in relation to not only intensity but length of exposure. The parts of sunlight that do damage to skin is call UVA and UVB rays, these rays are only slightly affected by cloud cover. These rays penetrate the skin and radiate for hours, causing radiation burns (sun burn.) Additionally, Titanium has the property of absorbing these rays, which is why it is in just about every sunblock available. Use the sunblock on a sunny day and not on the cloudy day and you will receive a higher dose of the sun's radiation, thus allowing one to get a worse burn on a cloudy day. The surface of the moon is covered in Titanium which is why it is so reflective and why the moon's light is safer than the sun's light, it reflects the visible light while absorbing harmfull UV radiation.

Answer 2

It's not that you get UV rays from the clouds themselves; it's that clouds are not as effective at blocking the short-length ultraviolet light as people think.

Look at it this way: if light can make it through the layer of clouds, than so can UV light. Which means that you can get a bad sunburn on even a cloudy day, if you don't take adequate precautions.

The general rule of thumb is that bright clouds are the equivalent of a sunscreen with SPF 4, and dark clouds are the equivalent of SPF 8 to 15. So if you're going to be out and about, make sure you still cover your skin or wear sunscreen.

One further note: spotty cloud cover can actually increase your UV risk, as the edges of those clouds can refocus the sun's rays. If any of the clouds in the sky appear shiny, especially around their edges, assume you're being exposed to UV radiation as much as if you were in direct sunlight.

Answer 3

No. I believe UV is scattered in all directions just as the other wavelengths, which means you can get burned even in the "shade". But either wave, UV is no more or less intense after passing through clouds.

Answer 4

Yes, UV rays can penetrate through fog and rain to reach the Earth's surface. However, the intensity of UV radiation is reduced under these conditions because the water droplets and particles in fog/rain can scatter and absorb some of the UV rays. It is still important to protect your skin from UV exposure even on cloudy or rainy days.

Answer 5

There are always tiny bits of UV radiation, but not enough to worry about.