Abstract
This study was carried out in Mosul city depending of the meteorological station records of Dohuk city since 1976 to 2010. while a large variation of annual precipitation during this period (212.4-888.6mm) while the annual precipitation during the study period was 525.5mm in which the dry and wet years were determined. in addition to the possibility and return period which were determined using the hazen formula. The return period of the large deficiency year was 9.5 year with probability of 10.2% while wet years which has amount of precipitation more than (656mm) has frequency one time within (3.8) year with probability equal to (26.5%). Results also showed that there was a reverse correlation between annual mean temperature. winter mean temperature and annual precipitation water balance of the last ten years showed that there was severe water deficiency and limited water surplus.
