Weather. The whole world lives under one sky at a time, but the land decides how it falls.
Rain over open ground, snow over permafrost and drought over sand and savanna, all in the same month.
Snow. Any weather that reaches cold land falls as snow: it drifts down slowly and the wind carries it much further than rain.
Seasons. Temperature swings from deep winter to high summer, so the poles freeze while the equator never does.
Wind. One direction for the whole world, turning every 2 to 4 years, and precipitation slants with it.
Storms, with rare lightning.
Deadwood. Trees killed by drought stay standing, dry and grey.
Three weather brushes: rain, heat and frost.
A weather brush also shifts the climate of the region, so enough of it turns forest into savanna over decades, or walks the land back down to permafrost.
A new world law, Weather, that switches the whole system off.
Weather is kept in the save and continues where you left it.
Rain puts out fires. Until now nothing in the game could stop one except time.
Rain adds 30% to a village harvest.
Drought halts all plant growth, dries up shallow water and cuts harvest by 40%.
Drought doubles how fast an existing fire spreads, but never starts one itself.
Frost cuts a village harvest by 60%, and can kill it outright instead, with a coin flip each month.
Ground colder than the freezing point yields nothing at all, so the far north starves through winter and lives through summer.
Deadwood catches fire more easily than living trees, and woodcutters will take it for firewood.
The temperature layer, generated with every world and never read by anything, now drives the whole system.