NPCs also all have their own routines they follow, and react to the weather. They also react to what you do. They respond differently if you're naked or if you're throwing a bomb near them or swinging a weapon. Hell they even try to talk you out of suicide if you're standing on the edge of a bridge and they walk by. I love that the weather also makes you have to adjust your strategy. Have to avoid climbing steep slopes until the rain stops, but you can sneak around monster camps a lot better. Better hide during a thunderstorm if you only have metal weapons. The entire world feels so very alive for being so vast and large.