The study looked at how dry or wet different parts of Iraq are by analyzing temperature and rainfall data from 1981 to 2015. They used different aridity indices to classify the climate, finding that most of Iraq is hyper-arid, arid, or semi-arid. Only a small area is dry sub-humid, moist sub-humid, or humid. The climate varied by season, with winter being semi-arid to very humid, spring arid to humid, autumn mostly arid, and summer the driest. The arid and hyper-arid areas increased from 1981-1997 to 1998-2015, especially in the north of Iraq.