Wind roses are graphic tools that show the frequency of wind speed and direction at a location. They depict the percentage of time winds blow from different compass directions within concentric circles, with color bars indicating wind speed ranges. The spokes with the longest lengths on the wind rose indicate the most frequent wind directions. Wind roses provide a useful way to summarize large amounts of wind data in a single plot.

1. WIND ROSES
 Wind rose is a graphic tool to give a short view of how wind speed &
direction are typically distributed at a particular location.
• Wind roses were followed after
compass rose.
• Compass rose is a fig on compass,
to display orientation of cardinal
directions & intermediate or
intercardinal directions.
COMPASS ROSE
Cardinal directions – N,S, E & W
Intercardinal direction – NE, SE, NW, WS.
Secondary intercardinal - NNE, ENE, ESE etc.

2. • The modern wind rose used by meteorologists gives the percentage of the time the
wind blows from each direction during the observation period.
Concentric circles represent percentage of time.
PARTS
The numbers around the outside edge of the circle represent
compass points.
N

3. The colour bars of the wind rose refer
to the speed of the wind in miles per
hour (mph)
• Concentric circles – time %
• Nos around – compass points ( direction).
• Colour bars – wind in mph.

4. • Using a polar coordinate system of gridding, the frequency of winds over a long time
period is plotted by wind direction, with color bands showing wind ranges.
• The directions of the rose with the longest spoke show the wind direction with the
greatest frequency.
Great frequency
Low frequency
• Useful representation coz a large quantity of details summarized in a single plot.
• 8 points of compass can be used to record the direction of wind, 16 points can be
used for more accuracy.
16 points are used

7. Include the wind
patterns in a particular
place of interest.
Include also the
instruments used to
measure winds.
Include the maximum
tabulated wind
velocitiess in Japan/
India. Monthly, yearly
and over the decade
etc. Any particulary
devastating winds may
be included with
sketches if available.