Windrose

http://nj.usgs.gov/grapher/tutorial/examples.html#windrose

Windrose graphs are used to display wind direction and speed for a specific location for a particular time frame. This graph is showing the wind data for Klamath Falls, Oregon from January 1st, 2006 through December 31, 2010. The windrose can tell you which direction winds traveled and the frequency at which they blew. They also can show you the wind speed and how long those winds occured. As you can see most winds flow North, Northwest and had a peak intensity of 18.64%.