Night/Day Cycle and Weather Simulator with Multi-Layer Skydomes for BGE,
very Fast! all Triangles, all NoCollision, all single-layer .DDS power of Two Textures (DTX1 and DTX5), Shadeless when allowed or Phong,
GLSL ready, Python Code, GLSL Shaders, Easy to use, parented to a central Empty,
Named Objects, includes Rain Shader, includes GLSL reflecting and moving water,
randomly it gets Cloudy and/or Rainy, Rain reduces view distance like real life,
Moon, Sun, Stars, Clouds, everything moves independently, Blender >= 2.6.3a ,
Rain particles can be changed to make Snow. Please consider im new to Blender. Its Libre.
Download, open, press P, look around, wait a little, eventually can rain or get cloudy 
http://www.pasteall.org/blend/13858