Rain, thunder storms, and humidity so thick that you can cut it with a knife. And, when it isn't raining, the heat is magnified by the humidity. Oh, and all of my Californian friends and family have NO idea what real rain is like. I mean, for the past 23 years I had no idea what real rain was like. Imagine approximately two months of rain like this... but even harder:
(Video taken by me from an apartment in Seoul)