WINDROSE

http://www.climate.washington.edu/climate.html

A windrose is useful to visually portray the frequency of wind direction. In the above image the wind blew out of the south approximately 13% of the time. This wind rose also adds in the wind sped with the frequency of the wind direction. The more color means the wind speed occurred more often. On this wind rose the most frequent wind occurrence was a 7 to 11 know south wind.