Depends on clouds and what not. there are many different looks in this game for rain or even dry weather. I don't know about full on night time looking though. The stone in Novigrad gets a lot darker when its soaked with rain if that's what you mean.
Honestly though, the attention to every little detail in this game is amazing. There really didn't need to be 50 different types of weather, or all the detail in every single piece of armor or clothing. Even the owl, its the only one in the game and all its animations and the blinders it wears and every thing are just so detailed its crazy. Would have likely been GOTY with half the effort but as it is now, it's set a new standard that many studios are going to have a really hard time matching.