[Zenbit_UX]

Worth noting here for any readers new to UV guidelines that the above rule isn’t necessarily helpful for you. I’m currently traveling in an area that is 8:30am-4:30pm and live in an area that’s 10-6 pm in the summer and shifts throughout the year.

The actual rule is derived from your location’s safe UV index zones, which is found out by determining what local time the UV Index <= 2. Above 2, wear some amount of protection.

[sevenseacat]

That's basically sun up to sun down, here.

It's been completely grey, overcast, and raining here all day and the UV index sat between 3 and 5.

[flyingshelf]

The worst sunburn I ever got was on a boat while overcast. I don't trust them clouds no more.

[plorkyeran]

Clouds block a decent amount of UV on average, but it’s much less consistent than you might expect. 9/10 you might be completely fine with no sunscreen and then get a horrible sunburn the tenth, with no apparent visual distinction between them.

[Zenbit_UX]

Ya, the relationship between UV and sunlight is strange and unintuitive. For that reason I use a UV widget on my lock screen.

I find that being exposed to the value (e.g. 4) while being able to see the suns effect (e.g. cloudy) gives me a better feel for conditions.