"Contrary to health promotion messages on UV safety, clouds do reduce the amount of UV we experience."
Do you take into account UVAs as well? As far as I know they are not as affected as UVBs in this scenario or are they?
I've read in another post of yours that the UVI could even decrease by more than 50% if the sun is completely obstructed by clouds, but how much is the minimum decrease? Meaning, if the clouds are just enough to keep my shadow from appearing, is it a 50% decrease in that case or what?
I'm just trying to figure out a minimum percentage to use, so for example if the UVI is 4, I know that with clouds I always get 2 or less, and I plan my sun protection accordingly, so maybe, in that case, if I stay out for 1 hour, I know I won't get 1MED even without sunscreen.
Thanks Richard, very interesting as usual!
When you say:
"Contrary to health promotion messages on UV safety, clouds do reduce the amount of UV we experience."
Do you take into account UVAs as well? As far as I know they are not as affected as UVBs in this scenario or are they?
I've read in another post of yours that the UVI could even decrease by more than 50% if the sun is completely obstructed by clouds, but how much is the minimum decrease? Meaning, if the clouds are just enough to keep my shadow from appearing, is it a 50% decrease in that case or what?
I'm just trying to figure out a minimum percentage to use, so for example if the UVI is 4, I know that with clouds I always get 2 or less, and I plan my sun protection accordingly, so maybe, in that case, if I stay out for 1 hour, I know I won't get 1MED even without sunscreen.