A wind rose gives a very concise but information-laden view of how wind speed and direction are typically distributed at a particular location. Presented in a circular format, the wind rose shows the frequency of winds blowing FROM particular directions. The length of each "spoke" around the circle is related to the frequency of time that the wind blows from a particular direction. Each concentric circle represents a different frequency, emanating from zero at the center to increasing frequencies at the outer circles.

A wind rose gives a very concise but information-laden view of how wind speed and direction are typically distributed at a particular location. Presented in a circular format, the wind rose shows the frequency of winds blowing FROM particular directions. The length of each "spoke" around the circle is related to the frequency of time that the wind blows from a particular direction. Each concentric circle represents a different frequency, emanating from zero at the center to increasing frequencies at the outer circles.

This rose shows that the winds at Chennai during the period blow from the southeast much of the time. In fact, the 3 spokes around the southeast direction (ESE, SE and SSE) comprise 39% of all hourly wind directions. This is quickly calculated by taking the sum of the frequencies of each of these directions (13+16+10=39%). This also shows that the wind rarely blows from the northwest. These wind roses also provide details on speeds from different directions. Examining winds from the southeast (the longest spoke) one can determine that approximately 1% of the time the wind blows from the southeast at speeds between 3.6 and 7.2 kilometer per hour. Similarly, on this spoke it can be calculated that winds blow from the southeast at speeds between 7.2 and 10.8 km/hr about 3% of the time, at speeds between 10.8 and 18 km/hr about 7% of the time, between 18 and 28 km/hr about 5% of the time.