Strong winter winds lifted large clouds of dust from the Sahara and carried them across the Mediterranean to Europe during March 2026. When Saharan dust collided with moist weather systems, so-called “dirty rain” fell in parts of Spain, France and the United Kingdom, leaving a brownish deposit on vehicles, buildings and other surfaces.
The movement and concentration of dust between March 1 and 9 are shown using the GEOS (Goddard Earth Observing System) model, which combines satellite observations with mathematical models of atmospheric processes. The data shows the density of dust in the air column, that is, the amount of particles that are in a certain volume of the atmosphere.
Saharan dust covered a large part of Europe
The model shows that the dust clouds originated in northwestern Africa, from where the winds carried them towards the Atlantic Ocean, but also to the north across the Mediterranean. Over the course of several days, the dust spread across Western Europe. Residents reported hazy skies and unusual sunrise and sunset colors from southern England to the Alps in Switzerland and Italy, where a layer of dust was visible even near the Matterhorn mountain.
Part of the dust did not remain in the atmosphere. When storm systems encountered these particles, the rain pulled them toward the ground. A low-pressure system called Storm Regina, registered by the Portuguese Meteorological Service in early March, brought so-called “blood rain” to southern and eastern Spain, as well as parts of France and southern England.
In the upper layers of the atmosphere above the Mediterranean, clouds known as “dusty cirrus” were also formed. Dust particles in them act as condensation nuclei for ice crystals, which affects cloud formation and climate processes. Scientists study these phenomena to better understand their impact on weather, climate and solar energy production.
An analysis based on the NASA MERRA-2 model and MODIS satellite data showed that Saharan dust can significantly reduce the efficiency of solar power plants. A study conducted in Hungary found that solar energy production during days with high dust concentrations can drop to around 46 percent, while in cleaner conditions it reaches more than 75 percent.
Researchers warn that in recent years, increasingly frequent and intense winter intrusions of Saharan dust into Europe have been recorded. Drier climatic conditions in northwestern Africa and weather patterns that increasingly direct winds from the Sahara towards the European continent are cited as possible causes, NASA announces.