Right now the Night is just a 5 minute time of darkness, but nothing dangerous really happens. I suggest you add some crazy powerful NPCs that spawn at night and murder all players on sight to bring an element of fear! You could also expand the time of the night to be 10-15 minutes long so the adventures are lasting. Solo players should have no chance when encountering these beasts but a group of at least 3 people should have a fighting chance. The new NPC’s should also be resourceful when farmed but dangerous even for a level 60 when alone!
Even the sand storm should have crazy creatures that come out. I also think the North should have a blizzard with something like yeti come out in white out conditions.