bored again and i try to be creative:
climate in jade? there is more to it than just rain and the drakeling and cold. Which races are more adapted to the cold or heat? I can't think of an orc liking heat more than a troll, so maybe just a random (or not) birth and growing up place/region or climate will give the character different resistance to cold or to heat. While this might not affect the game too much in normally, it can make it easier for mountain born pc to cross a glacier than a desert and vice versa.
Affected could be: Walking speed, food consumption, thirst?, healing rate, and i don't know what more? Possibility of sickness, strength loss (carrying capacity diminishes temporarily, take that plate mail off - or does it freeze and you can't really use it anymore...).
In the very extreme most pc's need to prepare to cross a certain desert to not loose health or toughness in the long run - could mean having support of certain types of potions or gear, those others used to it might just make it.
This brings up seasons that are better for certain regions. Like on our planet, in some times, some places should be avoided. On the other hand, overworld lakes could freeze.
Climaticly different regions may be favourable for hosting specific monsters, or benefit their combat abilities.
Frost and fire spells gain some other uses, and become less or more powerful if the environment is too extreme. I mean, freezing someone in a freezing environment sound like another hoax.
All this I would think of existing on a soft scale, like assigning every place in the wilderness a certain temperature value (and a certain humidity???, wind?? ok now it gets maybe too complicated) that might be a function of the day of the year ( or the typical mean value and standard deviation of a dice roll ? the dice only needs to be rolled upon entering a square. )
Btw, booze gets a new use, too. Oh, and the survival talent.