Windfall

Wind in the enhanced outdoors that changes by the day: trees and plants sway and shiver by their kind, some days turn windy or stormy, gusts come and go with their own sound, leaves blow off the trees and snow off winter boughs.

Windfall is an entry in the Built-in mods database, listed under On.

Several of these change core rules, so the guide pages describe the game with them on. 'Fixed by the room' means online everyone plays with the mod at its shipped settings, whatever they choose offline.