Substantial quantities of Sahara desert dust are forecast to hit Europe over the weekend, the Copernicus Atmosphere Monitoring Service (CAMS) says.
Large plumes of dust are on their way to south and central Europe, CAMS said on Friday.
The dust would likely "reach from southern Europe up to Scandinavia and significantly affect air quality in Spain, France and possibly the UK and Benelux countries," CAMS senior scientist Mark Parrington said.
"While the degree of visibility of the dust is not certain, the event will have impacts on local air quality," CAMS said.
The agency, which is funded by the European Union, said similar events observed in the past had significantly affected the air quality of areas.
"The high concentrations of dust can have health impacts on the respiratory systems of all people in the affected regions and add to particulate matter air pollution from local sources," Parrington said.
CAMS added the dust could lead to "red skies, limited visibility or stains on cars and windows from dust deposition," though it was difficult to predict these effects in advance.