K Beauty sunscreens - how do they perform in hot weather?

[OvaHere]

I've always used more traditional spf 50 sunscreens on my face but recently I've bought a couple of Korean ones to try out.

First one I've tried is Beauty of Joseon and it feels amazing - like a lovely moisturiser and doesn't sting my eyes which a lot of sunscreens do. Also no issue with a white cast or being a bit tricky to sink in to the skin.

Obviously it's the middle of winter now but as someone who burns very easily and uses Retin A products I'm wondering how they perform at the height of summer? Are they really spf 50?

For casual daily use, perfectly well, South Korea tends to be a lot hotter and humid than here so it's well formulated for those circumstances. But if I know I'll be out in the sun for long (even if it's intermittent) on a high UV Index day and active like a city break or day out, then I'll opt for something else. It's not that the South Korean versions wouldn't hold up in those situations, but I want a maximum protection type thing for some extra assurance in those situations.

Thanks @botemp that's useful. A lot of the time I'd just be going to work and wearing it under makeup (which the formulation is perfect for) but for more sun exposure days I'll consider back up products.