recognition of spatial relationship of widespread hot days in iran

one of temperature estates is hot day occurrence. in order to recognize the mechanism of this estate, surveying its spatial behavior is crucially important. in current paper it has been attempted to recognized widespread hot days and their spatial distribution by using statistical methods. accordingly maximum temperature database of iran during 1962-2008 has been used. the analyses result has illustrated 1537 widespread hot days. most of these days have been occurred during winter and spring seasons. in order to recognize distribution patterns and spatial autocorrelation, global and local moran statistic and also getis- ord g* statistic has been used. using global moran has been revealed that in 99% confidence interval, cluster pattern governs the hot days frequency as well as hot days temperature. frequency clusters has been raised in centre of iran while clusters of the mean of temperature has been occurred in southern (from west to east) and northwest margin of the country. however the regions that experienced maximum frequencies of hot days do not happened in regions with hottest day’s temperature mean. generally hot days regions are determined by humidity, latitude and elevation. the hot spots are located in south, southeast and cold spots are founded in high lands and northwest of iran.