As I wrote in the other weather thread... ... there is no actual system behind the weather though. No weather progression or anything. Each time the open world loads, a weather state is randomly chosen. Not like in the Witcher 3, where there was, say, morning fog and such. Also: NPCs don't react to the weather, at all...
Not sure what you're saying here but the weather changes during the day. I did a mission with River and it was foggy and bleak to the point I couldn't see past a few yards, yet by the end of that mission clouds began to move gently and a nice sun peaked through. By the end of that day (I didn't use the wait system) it was back to normal clear sky.
The feature seems like it's there judging by my own playthrough, but maybe it's buggy ? Anyway I wouldn't expect as many weather changes as the Witcher given it's an urban setting in a rather small dry area.