Why do the Andes get bad weather? The Andes get bad weather because of the mountians. Here is how it works, on very tall and long mountain ranges there is a windward side and a leeward side. Because of the height the clouds can't go over the mountain. When something like this happens it creates the sides I was talking about before. What these sides are is, clouds (once they get dense enough) HAVE to precipitate (drop some form of water) since the clouds can't get over the mountains two things happen 1.) the clouds get denser faster 2.) the clouds' rain is all on one area Since all the rain is on one side that side gets really bad weather and is then considered t…