Paris, France Air Quality & Smog

Dominant pollutants, when pollution and smog are worst, a notable historical episode, and the official monitoring agencies for Paris, France — plus how to check the current reading. Paris 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), PM2.5 / PM10, summer ozone.

Seasonal pattern: when smog is worst

Paris's recurring problem is the winter particulate episode: cold, stable, high-pressure weather traps PM from traffic, wood heating, and (in early spring) agricultural ammonia. Traffic NO₂ stays elevated year-round, and ozone peaks on hot summer days. Severe episodes trigger emergency measures including alternate-day driving (circulation différenciée) and free public transit.

A notable air-quality episode

In December 2016, a prolonged particulate episode forced Paris to impose alternate-day driving restrictions and make public transport free for several days — one of the most severe pollution events in the city in decades, following a comparable March 2014 episode.

The local index and who runs it

Paris 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. Airparif publishes station-level readings and forecasts for the Île-de-France region; the EEA aggregates France into the common European Air Quality Index.

• Airparif (regional air-quality observatory)
• European Environment Agency (EEA)

How to check air quality in Paris

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 Paris air quality

Why does Paris have air-quality and smog problems?

Paris's recurring problem is the winter particulate episode: cold, stable, high-pressure weather traps PM from traffic, wood heating, and (in early spring) agricultural ammonia. Traffic NO₂ stays elevated year-round, and ozone peaks on hot summer days. Severe episodes trigger emergency measures including alternate-day driving (circulation différenciée) and free public transit.

What are the main air pollutants in Paris?

Paris's dominant pollutants are nitrogen dioxide (NO₂, traffic), PM2.5 / PM10, summer ozone. The reading on any given day is usually driven by whichever of these is highest.

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

In December 2016, a prolonged particulate episode forced Paris to impose alternate-day driving restrictions and make public transport free for several days — one of the most severe pollution events in the city in decades, following a comparable March 2014 episode.

What air-quality index does Paris use?

Paris 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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