This page shows the global average precipitation (rain). On this page you can find two kinds of visualizations. The first one shows an animation that shows the precipitation for each month of the year. The second one is a static image showing the global annual average precipitation.
When you take the amount of precipitation for each month, and divide it by the amount of months you get a general idea where the most rain falls in a year. Of course the sahara and the middle-east stick out, but apparently also chili is a bit dry. Which apparently is called the Atacama Desert and is one of the dryest places on the earth.
The same scale, shown below the image, applies here as we've used for the previous series of images.