Weather should exist in game, at the moment walls exist only to hang pictures off.
In temperate northern european style climates it should rain quite often, most indoor furnishings and appliances should be destroyed if left in the rain too long. Sims left outside at night, or in snow or rain, should get cold and eventually die if not brought indoors and warmed up.
You see all these legacy challenges where people just have their bed and a PC outdoors in the garden. Apart from the odd dry summer's day that shouldn't work !