The sirocco (also spelled scirocco) is a south or south-easterly wind born in the Sahara Desert that crosses the Mediterranean Sea toward southern Europe. At its source it is extremely hot and dry, with temperatures exceeding 45 °C in North Africa, but as it crosses the sea it absorbs moisture and arrives at European coasts as a warm, humid, and oppressive wind.
Mechanism and trajectory
The sirocco develops when a deep depression sits over the western Mediterranean, creating a pressure gradient that draws Saharan air northward. The air rises over the Atlas Mountains, descends to the North African coast, and crosses the sea in 12-24 hours. During transit it carries vast quantities of suspended mineral dust, causing the haze and mud rain events common in Spain, Italy, and Greece.
On the Iberian Peninsula, the sirocco primarily affects the Mediterranean coast and the Balearic Islands, where it can raise temperatures 10-15 °C above normal in just hours. It brings an oppressive sensation, milky skies, and reddish dust deposits on vehicles and surfaces. The most intense episodes degrade air quality, exacerbate respiratory conditions, and reduce visibility below 1 km.
In North Africa the same wind is known as ghibli (Libya), chergui (Morocco), or khamsin (Egypt). These are regional variants of the same Saharan airflow. See also: Fohn effect, air mass.