Windrose

A windrose is used to show the information about the distributions of wind speeds, and the frequency of the varying wind directions.
A wind rose may also be drawn for 8 or 16 sectors, but 12 sectors tend to be the standard set by the European Wind Atlas.

The radius of the wide outermost wedges gives the relative frequency of each of the wind directions, or per cent of the time is the wind blowing from that direction.

The second wedge tells you how much each sector contributes to the average wind speed at our particular location by taking the the same information from the first wedges then multiplying each by the average wind speed in each particular direction. The result is then normalised to add up to 100 per cent.

The innermost (red) wedgetells you how much each sector contributes to the energy content of the wind at our particular location by again taking the data of the first this time multiplying it by the cube of the wind speed in each particular location. The result is then normalised to add up to 100 per cent.