The hourly mean wind speed data for Ali Algharbie station locations in south east of Iraq are collected and analyzed over a period of 1 year. The Data are fitted to the Weibull distribution function which is considered as the infrastructure to form a wind atlas for any country obtaining the Weibull distribution is necessary to determine the shape ( k) and scale( c) parameters. There are several methods that can be used to determine these parameters. This paper presents the comparison between two methods, Graphical method and the new method is called Energy Pattern Factor (EPF) method. It is found that the highest value of the shape ( k) and scale (c) in Jun. at the two methods and the lowest value in Oct. at the two methods and this corresponds with the highest (8.597m/s) and lowest (3.265m/s) value of hourly mean wind speed in these months. So the new method shows good agreement compared with the result of the Graphical method therefore, we recommend using this method to calculate the Weibull distribution parameters.