In this study, the two Weibull parameters of the wind speed distribution function, the shape parameter k (dimensionless) and the scale parameter c (m s(-1)), were computed from the wind speed data for Izmir. Wind data, consisting of hourly wind speed records over a 5-year period, 1995-1999, were measured in the Solar/Wind-Meteorological Station of the Solar Energy Institute at Ege University. Based on the experimental data, it was found that the numerical values of both Weibull parameters (k and c) for Izmir vary over a wide range. The yearly values of k range from 1.378 to 1.634 with a mean value of 1.552, while those of c are in the range of 2.956-3.444 with a mean value of 3.222. The average seasonal Weibull distributions for Izmir are also given. The wind speed distributions are represented by Weibull distribution and also by Rayleigh distribution, with a special case of the Weibull distribution for k = 2. As a result, the Weibull distribution is found to be suitable to represent the actual probability of wind speed data for Izmir (at annual average wind speeds up to 3 m s(-1)). Copyright (C) 2002 John Wiley Sons, Ltd.