Weather that changes during the day like starts of dry and sunny then it gets overcast and then it Rains or Snows depending what season you are in.
I would second this request, Dynamic weather system really adds an emersion factor that is missing . A good example both visually and overall how it works can be seen in Forza Horizons 3 drive around for a few hours in that game and the dynamic weather and the way the skybox reflects it is just superb.
