Iran is one of the world's arid regions and exposed to dust particles in the air. This is important in spatial and temporal terms as well as the affects human health. In this paper a day when due to the amount of dust particles visibility reduces to 5,000 m is considered the dusty day. In the spatial and temporal analysis of dusty days 38 synoptic stations were studied. In order to conduct data spatial changes analysis, monthly and annual maps were drawn using interpolation method. Maximum number of dusty days was in Zabol station 165.95 and then Dezful with 108 dusty days was the second highest. Rasht, with the average of 1.024 day shows the minimum number of dusty days. Studying scattering map of the average dusty days show that Zabol and Dezful have maximum dusty days during study period. According to interpolation half southern regions of Iran especially eastern and western borders have the maximum dusty days while northern and northwestern regions show the minimum number of dusty days.