Last checked: 6 October 2026
The short answer: Calima is Saharan dust carried on the wind from North Africa. In Valencia it turns the sky hazy and yellow, can coat cars and terraces in muddy “blood rain”, and pushes up levels of fine particles in the air. Episodes are usually short. On a calima day, cut back on hard outdoor exercise, keep windows closed if you have asthma or another breathing condition, and check the air quality before heading out.
Key facts
- Calima is fine sand and dust lifted from the Sahara and carried across the Mediterranean and the Atlantic. (Calima Canarias)
- The most intense episodes on record in Spain came between 2020 and 2022, clustered in late winter and early spring, including 15–16 March 2022 on the mainland. (CSIC, October 2024)
- During those episodes, PM10 particles reached close to 5,000 micrograms per cubic metre in some places. The World Health Organization’s guideline for a 24-hour average is 45. (CSIC, same report)
- People with asthma or other respiratory conditions, older people, children and pregnant women are the most affected.
- Valencia’s city council advises avoiding intense outdoor activity, keeping windows closed, and wearing a mask outdoors if you have breathing problems. (Ajuntament de València)
- Rain usually clears the dust from the air, but can leave a yellowish layer behind.
- Some mornings in Valencia, you look up and the famously blue sky has turned the colour of weak tea. That’s calima: dust from the Sahara, carried hundreds of kilometres on the wind. It can look dramatic, even a little apocalyptic, and it does affect the air you breathe, so it’s worth knowing what it is and what to do when it arrives.
Hazy, yellow skies and “blood rain”
Calima starts in North Africa, where strong winds lift fine sand and dust from the Sahara into the atmosphere. It is most common in the Canary Islands, but the dust clouds can travel across the Atlantic and the Mediterranean to mainland Spain and Portugal.
The dust gives the sky a hazy, reddish-yellow tint. When it mixes with rain, it falls as a muddy residue sometimes called “blood rain”, which streaks cars, windows and terraces. In stronger episodes, visibility can drop sharply.
How it affects your health
The high concentration of airborne particles during calima can affect your health, especially if you have a respiratory condition such as asthma.
| Who | What to do on a calima day |
|---|---|
| Everyone | Cut back on hard outdoor exercise, such as running or cycling |
| Asthma or other breathing conditions | Stay indoors where possible, keep windows closed, wear a mask (FFP2) if you go out, and keep your medication to hand |
| Older people, children, pregnant women | Limit time outdoors during the worst hours |
| Drivers | Slow down if visibility drops; consider sharing car journeys to reduce extra pollution |
How to check the air quality
For live readings near you, the European Environment Agency’s European Air Quality Index shows monitoring stations across the Valencia area, including PM10 levels. AEMET forecasts dust episodes, and Valencia’s city council posts advice on its social media channels when an episode arrives.
Calima events are usually temporary, and in Valencia they rarely last long. Rain often clears the dust from the air, although it may leave a thin, yellowish layer behind. Hold off on washing the car until it’s over.
FAQ
Saharan dust lifted by the wind in North Africa and carried over Spain. It turns the sky hazy and yellow and raises the level of fine particles in the air.
It raises particle pollution, which mainly affects people with asthma or other respiratory conditions, older people and children. For most healthy adults, cutting back on strenuous outdoor exercise is enough.
Rain mixed with Saharan dust. It falls as a reddish, muddy residue on cars, windows and terraces.
Usually a day or two. Rain or a change of wind normally clears it.
Valencia’s city council recommends a mask outdoors if you have breathing problems. An FFP2 mask filters fine particles best.
It can happen at any time of year, but the most intense recent episodes came in late winter and early spring.
Related guides
- New in Valencia: Guides for Settling In
- Valencia and DANA: What Every Resident Should Know
- Sails and Winds: Making Sense of Valencia’s Weather
Sources
- Calima Canarias — What is calima?
- CSIC — Supercalimas study (29 October 2024)
- Ajuntament de València — Calima precautions
- European Environment Agency — European Air Quality Index
- AEMET
Image courtesy of Copernicus Sentinel data 2022, Attribution, via Wikimedia Commons
