Madrid, Spain Air Quality & Smog

Dominant pollutants, when pollution and smog are worst, a notable historical episode, and the official monitoring agencies for Madrid, Spain — plus how to check the current reading. Madrid reports air quality on the European Air Quality Index — our full guide explains how that scale works and how it compares to the US AQI.

Dominant pollutants

Nitrogen dioxide (NO₂, traffic), summer ozone, Saharan dust (PM10).

Seasonal pattern: when smog is worst

Madrid's defining problem is traffic NO₂, which on still winter days forms a visible brown cap — the "boina" — over the city. Summer heat drives ozone, and spring brings episodic Saharan dust ("calima"). The city has used low-emission access restrictions (Madrid Central, now Madrid 360) to cut central-area traffic.

A notable air-quality episode

In March 2022, an exceptionally intense Saharan-dust episode turned Madrid's skies orange and pushed PM10 to some of the highest levels on record across Spain — see our Saharan Dust guide.

The local index and who runs it

Madrid reports air quality using the European Air Quality Index, not the US AQI — so the same air can read as a different number than you may be used to. Madrid's city network publishes hourly station data and triggers traffic restrictions during NO₂ episodes; the EEA aggregates Spain into the European Air Quality Index.

• Ayuntamiento de Madrid (city air-quality network)
• MITECO (national ministry)
• European Environment Agency (EEA)

How to check air quality in Madrid

For the official live reading, the agency portals above are the canonical source. To understand what the numbers mean, start with our guide to the European Air Quality Index and the broader comparison of world air-quality indices. Smog Report puts glanceable air quality on your iPhone — widgets, Live Activities, Siri, and Apple Watch — free and with no account.

Common questions about Madrid air quality

Why does Madrid have air-quality and smog problems?

Madrid's defining problem is traffic NO₂, which on still winter days forms a visible brown cap — the "boina" — over the city. Summer heat drives ozone, and spring brings episodic Saharan dust ("calima"). The city has used low-emission access restrictions (Madrid Central, now Madrid 360) to cut central-area traffic.

What are the main air pollutants in Madrid?

Madrid's dominant pollutants are nitrogen dioxide (NO₂, traffic), summer ozone, Saharan dust (PM10). The reading on any given day is usually driven by whichever of these is highest.

Has Madrid had a major air-quality or smog event?

In March 2022, an exceptionally intense Saharan-dust episode turned Madrid's skies orange and pushed PM10 to some of the highest levels on record across Spain — see our Saharan Dust guide.

What air-quality index does Madrid use?

Madrid reports air quality on the European Air Quality Index (European AQI), not the US AQI — so the same air can read as a different number than you may be used to. For live, glanceable readings on your iPhone, the free Smog Report app auto-selects the right local index for wherever you are.

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