You need both weather mods installed, but only All Natural Base.esm and optionally All Natural - Real Lights.esp and All Natural - Indoor Weather Filter For Mods.esp active. Choose the vanilla-est of options from All Natural's installer and make sure you also have NAO's resources installed.

Optimization files like the real lights pathing fix and rain box fixes are encouraged.

No promises on any updates since I'm not accepting donation points for this, but feel free to drop a comment with any issues and I'll help out if I can.