Quote Originally Posted by JoeyD473 View Post
I am working on a world map in ft3 and would like to know what affects average rainfall of an area besides proximity to large water sources
Prevailing wind, temperature and temperature changes, and changes in elevation (The windward side of mountains is wet, the leeward side is a "rain shadow").

Wind is in turn controlled by pressure (Controlled by temperature, particularly due to latitude, surface albedo, thermal reservoirs, and season), and Coriolis forces.