EXPLANATION OF BLUE ROSES.
The wind roses in blue color are located in the centre of each 5 degree square. Each rose shows the distribution of the winds that have prevailed in the area over a considerable period of time. The wind percentages are summarized for calm and for the Cardinal and Intercardinal compass points. The arrows fly with the wind, indicating the direction from which the wind blew. The length of the shaft, measured from the outside of the circle to the end of the visible shaft (not necessarily to the end of the last feather), using the appropriate scale below gives the percentage of the total number of observations in which the wind has blown from that direction. The number of feathers shows the average force of the wind on the Beaufort Scale. The figure in the centre of the circle gives the percentage of calms. When the arrow is too long (over 29%) to fit in the 5 degree square, the percentage is indicated numerically on the shaft.