Proportional Circle Map

http://hmbmaps.blogspot.com/2009_06_01_archive.html

The data in a proportional circle map is shown in circles. The size of the circles depends on the how much the data is showing; the bigger circles represent higher data values and smaller circles represent lower data values. In the map above, the circles represent the amount of rainfall in Florida in twenty four hours. The bigger circles in on the west coast shows a large amount of rainfall in that region.