Weather affects your character's actions. Surfaces may be more difficult to climb, or easier. Locks may be frozen solid. All manner of creatures can ambush from under the snow, or piles of autumnal leaves.
@golgaloth And everyone's favorite, frostbite. ;)
@joypainlife As an Australian, Heatstroke is my personal fave to drop on heavily armoured knights and paladins.
@golgaloth Ain't biology fun? ;)