My morning shade disrupted by clouds?

Question

This is quite mundane. Recently, in the mornings, I enjoy shade from a large tree. Within this shade I go about my morning routine.The sun beats hard this time of year. This morning was cloudy, and as such there was no shade. Of course the sun was still behind the tree top, just shrouded by cloud.I felt the heat on my skin, and it was obvious I&rsquo;d get burned before long.I hadn&rsquo;t considered this before; is it possible that the blanket of cloud is diffracting the sunlight, and makes the clouds themselves a source of UV, as opposed to a singular source (the sun).Would this explain why I&rsquo;m being burned despite the sun being hidden behind the tree canopy (and clouds)?I never considered that clouds could be negative for seeking shelter from the sun.

PaulHoule · Accepted Answer

I always thought it was strange that people called red a warm color and blue a cold color although blue has a higher color temperature.
Then it hit me that the blue sky is actually cold, that is, the incoming energy flux of blue light is less than the black body radiation from the ground or your skin to empty space.
If you are in the shade on a hot day but can see the blue sky you radiate a significant amount of energy that makes you feel cooler.

MrGuts · Answer

UV can go through clouds. Wear sunscreen, or stay out of the sun.https://www.dignityhealth.org/articles/can-you-get-a-sunburn...