Explanation of Wind Rose tables

"Percentage frequency of wind by direction in selected speed increments by month"


Explanation:
Percentage frequencies for winds from 16 directions, in 6 different speed
increments. The "TOTAL" column at the right hand edge provides the percent of
time the average wind blew from each direction, regardless of speed. The "AVE
SPEED" column gives the average speed for each direction. The "TOTAL" row at
the bottom shows the percent of times wind speeds were within each speed
increment, regardless of direction. Any additional percentage of time is when 
winds were calm.

For example, refer to Astoria for January. The wind blew from the north at speeds 
of 1.0-3.5 knots for 0.2% of the time. The total time from the north was 1.3% and the 
average speed from that direction was 2.9 knots. In contrast it blew from the southeast 
7.7% of the time and averaged 4.3 knots. The January wind blew 6.5 to 10.5 knots 28% of 
the time and above 10.5 knots a total of 19.4 + 5.4 + 2.4  or 27.2% of the time.