Swimming in the un sounds rather unpleasant. Might want to swim in water instead.
Seriously - one can get very sunburned whether there are clouds present or not. Cloudy skies also make it a bit harder to see any underwater obstructions (if swimming in a lake, river or such). Cloudy skies are, however, a bi easier on the eyes due to less reflection (however, UV rays are still present).
As a general rule overcast is safer. but a bit less pleasant.
Onge my mom read a ladies magazine and started insisting we should wear more clothes at the beach. so we did, but did not take them off when we got in the water. Then she fussed about that.There is no pleasing some people.
Because people don't believe that there is as much chance of sunburn with overcast skies as there is on a sunny day, "it's best to swim on a sunny day," when you're more apt to pay attention to how long you've been swimming.
This post was edited by Benedict Arnold at August 22, 2018 12:18 PM MDT