If you follow current WHO guidelines for sun exposure, you will avoid UV almost anywhere on planet. Apple’s Weather app (based on those guidelines) recommends all day sunscreen in Stockholm this entire week; same in Singapore, where it is overcast and rainy.
This Swedish paper’s summary does not differentiate between UV and sun, but assuming it concerns UV—the guidelines will seriously have to change, and ASAP:
> Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking.
This Swedish paper’s summary does not differentiate between UV and sun, but assuming it concerns UV—the guidelines will seriously have to change, and ASAP:
> Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking.