Calima in Mainland Spain
Saharan dust intrusions, mud rain and live air quality across the Iberian Peninsula
Mainland Spain experiences 15 to 25 Saharan dust episodes per year. When these intrusions coincide with rain, the resulting mud rain (lluvia de barro) leaves an ochre residue on cars, windows and surfaces. The most affected regions are Andalusia, Murcia, the southeast coast, the Ebro Valley and the Balearic Islands.
What is calima in Spain?
Calima is the Spanish term for atmospheric haze caused by airborne dust. In mainland Spain, episodes occur when southerly winds carry Saharan dust over the Iberian Peninsula, reducing visibility and air quality.
Where does it happen?
Andalusia, Murcia, Madrid, the Ebro Valley and the Balearic Islands face the most frequent intrusions. Major events can affect the entire peninsula, reaching as far as Galicia and the Cantabrian coast.
When does it happen?
Spain experiences 15 to 25 Saharan dust episodes per year. They occur year-round but peak in spring and summer, when atmospheric conditions favour both dust intrusions and the rainfall that triggers mud rain.
What is mud rain?
Mud rain (lluvia de barro) is rainfall that carries suspended Saharan dust to the ground, leaving an ochre or red residue on cars, windows and surfaces. It requires a dust intrusion and precipitation at the same time.
Mud rain (Lluvia de barro)
Also known as blood rain, red rain or Saharan rain.
How it forms
Mud rain needs two ingredients at once: a Saharan dust intrusion in the atmosphere and a precipitation event. Saharan dust is lifted by desert storms and transported to Spain at altitudes between 1,500 and 5,000 metres. When rain falls through this dust-laden air, the raindrops capture the particles in a process known as washout. When the water evaporates, a thin ochre or red layer of mineral dust remains on every exposed surface: vehicles, windows, hung laundry and vegetation.
Why it matters
Mud rain reduces visibility, lowers solar panel output by soiling the glass, and worsens air quality during the dust intrusion. Paradoxically, the rainfall itself cleans the air by washing particles to the ground. The mineral deposits include iron and phosphorus, which can fertilise soil but stain vehicles and façades.
Cleaning tips
Do not use windscreen wipers on a dry windshield: the dust is abrasive and will scratch the glass. Rinse with plenty of water first, then wash normally. Cover outdoor furniture and pools when an intrusion is forecast. Clean air filters more frequently after intense episodes.
Major mainland episodes
Documented Saharan dust events across the Iberian Peninsula
Peninsula-wide March 2026 intrusion
An African dust mass driven by a low-pressure system southwest of the Iberian Peninsula covered almost all of mainland Spain and the Balearic Islands. Wet deposition of dust — mud rain — was forecast across most of the peninsula and both island archipelagos.
Source: MITECO / IDAEA-CSICPeninsular Supercalima
A dust mass from Algeria crossed the Iberian Peninsula from southeast to northwest. Levels reached 1,500 to 3,100 µg/m³ in Almería and 800 to 950 µg/m³ in Salamanca, Ávila and Valladolid: over 30 times the WHO 24-hour safety limit of 45 µg/m³.
Source: CSIC / IPNA studyAir quality by region
Real-time PM10 and calima status for major mainland Spanish cities.
Live calima status for your city
Real-time air quality and 5-day forecast for major mainland Spanish cities.