Iraq was again covered in a thick sheet of orange on Sunday after it suffered the latest in a series of dust storms that have become increasingly common.
Dozens of people have been hospitalised with respiratory problems in the centre and west of the country.
A thick layer of orange dust settled across streets and vehicles, seeping into people's homes in Baghdad.
The weather service said that flights were grounded because of poor visibility at airports serving Baghdad and the Shiite holy city of Najaf, with the phenomenon expected to continue into Monday.
The Civil Aviation Authority spokesperson, Jihad al-Diwan, said that flights have been interrupted at the airports of Baghdad and Najaf because of the dust storm.
Visibility was cited at less than 500 metres, with flights expected to resume once the weather improves.
The majority of hospitals in Najaf had received 63 people suffering from respiratory problems as a result of the storm, a health official said.
Another 30 hospitalisations were reported in the mostly desert province of Anbar in the west of the country.
In April, Iraq was hammered by a series of such storms, grounding flights in Baghdad, Najaf and Arbil and leaving dozens hospitalised.
Amer al-Jabri, Iraq's meteorological office, previously said that the weather phenomenon is expected to become 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 say these factors threaten to cause social and economic disaster in the country.
In November of this year, the World Bank warned that Iraq could suffer a 20% drop in water resources by the year 2050 due to climate change.
In early April, Issa al-Fayad, an Environment Ministry official, had warned that Iraq could face 272 days of dust a year in the coming decades, according to the state news agency INA.
The ministry said that the weather phenomenon could be addressed by increasing vegetation cover and creating forests that act as windbreaks.