Very nice mod, I tried it for night driving with the shader mod and I found this one the best so far for night scenarios... I'd like to add some feedback to help make it better.
1. First of all I have to say I use Natural Graphics weather with a modified Mr. Alpem PP filter. I find those colours natural and I got used to it. In daytime, as the post #56 above shows, it's not bright enough and the colours are a bit off too for my taste. Of course there is a combination of different PP filters, monitors, etc. but for daytime driving I prefer what I use over this mod and GbW (which is very... yellow for me).
2. During night-time this mod was the best I have used, the stars look brilliant. I did find something strange with the sky textures, white lines, like if the texture had white pixels on the edge. Screenshot below shows it, although it's a bit compressed.
3. I can see what you are trying to do with the dynamic weather based on temperature, season, etc., but sometimes I feel like I would prefer presets. In the beginning I couldn't make a clear scenario, I always had fog and such. It was a bit frustrating jumping into the game, exiting, changing weather parameters, loading the game again, etc. I would keep the system you have but also consider adding a few static presets if possible.
All in all very interesting project and I can't wait what your next developments result. This is a nice time for AC. Keep it up.