[nonethewiser]

Thats a great question because recently I searched similar things when trying to learn about the risk of UV with kids. All sources basically concludes any direct exposure to the sun is bad for you (not just kids) because UV is inherently harmful and vitamin D can be gotten other ways.

Either this is overstated or everyone is behaving very recklessly. Maybe a mix of both. But more details on these levels would be good. I also wonder if they assume direct sunlight or if actual cloudiness is baked into the daily index values.