The storm erupted in the north of the country on Thursday, prompting the cancellation of flights serving Arbil, capital of the autonomous Kurdistan region.
As the storm swept south, it shrouded Baghdad and cities as far south as Nasiriyah in a ghostly orange.
In the capital, buildings and vehicles were covered in ochre-coloured dust, AFP journalists reported.
The storm has caused “dozens of hospitalisations across Iraq due to respiratory problems”, health ministry spokesman Saif al-Badr told AFP.
The director of Iraq’s meteorological office, Amer al-Jabri, said that while dust storms were not uncommon in Iraq, they are becoming more frequent “due to drought, desertification and declining rainfall”.
Iraq is particularly vulnerable to climate change, having already witnessed record low rainfall and high temperatures in recent years.
Experts have said these factors threaten social and economic disaster in the war-scarred country.
In November, the World Bank warned that Iraq could suffer a 20 percent drop in water resources by 2050 due to climate change.