In this paper, the homogeneity of the annual wind speed average time series, was investigated and categorized using the standard normal homogeneity test and cumulative deviation test in thirty-one Iranian weather stations during the period of 1981-2015. The results of the cumulative deviations test on the annual average wind speed time series confirmed the homogeneity only for the Ahvaz, Ardebil, Qazvin, and Isfahan stations. The stations were categorized based on different statistical methods, and by considering various.
The investigations showed that in Tabriz, Mashhad, Khorramabad, Gorgan, Tehran, and Urmia stations with observed moderate and high heterogeneities, the starting time of heterogeneity and their jumps are similar. At these stations, the starting year of the detected jump did not correspond with the year of their relocations; therefore, the wind speed jump couldn’t be explained by the relocation of the station. Hence, it seems that the sudden increase in wind speed was created by altering the wind measurement instruments or changing the unit of wind speed which are not recorded in the metadata of this stations. It is likely that the heterogeneity and the trend of the annual average wind speed time series for the weather stations were as a result of the inaccuracies of the land cover as well as urbanization growth in the vicinity of the weather stations.