Weather and shelter

Weather affects more than the view. Heavy rain reduces sight and damage dealt. Snow and blizzards can slow movement as well. These penalties apply on the overworld. Entering a separate interior removes them.

Cold resistance softens the movement, sight and damage penalties from snow, light snow and blizzards. A timed cold resistance buff removes those penalties while it lasts. Rain and sandstorms are outside that protection.

A small room enclosed by walls, windows and doors gets a roof automatically. Fences and fence gates leave the sky open, and a town wall does not roof the whole town. Standing under a roof on the overworld removes the weather sight penalty. The outdoor movement and damage penalties still apply there.

A fenced enclosure can keep ordinary land monsters and wild livestock from spawning inside it, even though it has no roof. Keep the boundary unbroken. Very large enclosures lose this protection once the connected area inside reaches 1,500 tiles.