This paper presents a case study of a new methodology to accurately characterize and predict the annual variation of wind conditions applied on Ichanda site, Tamil Nadu, India showing dual behaviour. The estimate of the distribution of wind conditions is necessary to quantify the available energy (power density) at a site, and to design an optimum wind farm. Wind speed frequency distribution for some sites with two distinct peaks is not represented accurately by the typical two parameter Weibull distribution. The wind characteristics of Ichanda has been analysed by using wind data recorded by meteorological mast installed at that location. By examining the analysis, it shows that wind speed distribution is not demonstrated precisely by two parameter Weibull distribution. A mixed Weibull probability distribution function (PDF) is applied to analyse wind speed frequency distribution in that region. This model can be applied to regions where the wind speed distribution presents a bimodal distribution to predict wind speed probability distribution and annual energy production accurately.