Saharan dust, known locally as calima, is expected to spread across large parts of Spain this week as a DANA (isolated high-altitude depression) sits west of the peninsula. The dust will arrive alongside a new heatwave starting Tuesday, bringing widespread muddy rain, particularly in Mediterranean and southern regions.
Forecasts indicate that calima will intensify from Tuesday through Thursday, spreading across the Mediterranean coast, the Balearic Islands, the south and center of the peninsula, and the Canary Islands. Residents in Catalonia, Comunidad Valenciana, Baleares, Murcia, eastern Castilla-La Mancha, Andalucía, Aragón, and Madrid will notice increasingly hazy skies. Dust may also reach northern interior provinces such as Navarra, Castilla y León, and La Rioja before a cooler air mass from the north begins clearing the atmosphere from Friday onward.
Storms are expected to develop each afternoon through Wednesday, especially in the eastern interior. Their interaction with suspended Saharan dust will likely produce muddy rain, sometimes called “blood rain,” across the interior of Catalonia, Comunidad Valenciana, Murcia, eastern Andalucía, and Castilla-La Mancha. Storms should weaken by Thursday, but the risk of muddy precipitation will persist until the calima retreats.
The episode follows a period of extreme heat that has already affected Spain. Authorities previously warned of record-breaking temperatures and heightened risks for vulnerable groups. Recent alerts highlighted the possibility of temperatures reaching 44°C in the south, as detailed in recent coverage of the ongoing heatwave. Spain’s national weather agency, AEMET, operates Meteoalerta, a system designed to provide detailed, continually updated warnings for hazardous weather up to 72 hours ahead. Its notices identify the phenomenon and expected intensity, along with the validity period and affected area, providing a regional picture as conditions develop. The current forecast points to the combined effects of heat and dust, alongside storms. These conditions can disrupt daily life and affect air quality, with travel also at risk across the regions concerned.
Calima is common in Spain, especially during summer, when southerly winds carry dust from North Africa. These episodes can reduce visibility, worsen respiratory conditions, and leave reddish mud on cars, buildings, and streets after rainfall. The phenomenon can be particularly disruptive in the Mediterranean basin, where heat and humidity combine with dust to create challenging conditions for residents and tourists. AEMET’s station observations include hourly readings for the previous 24 hours, as well as daily extremes and accumulated measurements from midnight, helping distinguish forecast conditions from recorded weather. Authorities typically advise limiting outdoor activity during peak calima and ensuring proper indoor ventilation. As the week progresses, incoming cooler air is expected to disperse the dust and restore clearer skies across the country.
