Fifty five years ago, on some TV game show broadcast from California, a woman won a tanning contest in which she would be given a special bathing suit baring one leg and arm, lay out in the California sun every other day, then be flown to Florida in the intervening days to do the same with the other arm and leg exposed.
At the end of two weeks, CALIFORNIA WON! Florida had cloud cover.
Wonder how that would do today.
That sure kept her busy, I imagine
cloud cover does not stop the tan, or the burn, makes it worse, because the skin does not get as hot from the infrared, but still cooks with the uv.