Worst air pollution Saint-Étienne, today and tomorrow
Today (9 August): Air quality in Saint-Étienne is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 4:00 PM (O3: 33.2/100).
Tomorrow (10 August 2026): Air quality in Saint-Étienne is medium. AQI improves to medium; O3 decreases to medium; all other pollutants stay as today. Pollution peaks around 4:00 PM (O3: 40.2/100). Airmine updates local air quality forecasts four times daily.
Get the full experience in the Airmine app.
Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
Follow your pollen exposure and performance with the free Airmine–Strava integration. See your pollen and air quality exposure for every Strava activity.
Saint-Étienne's air quality reflects its position in the enclosed Loire plain basin surrounded by the Massif Central mountains, with vehicle traffic on the A47 and the legacy of coal mining and arms manufacturing generating background industrial PM2.5 alongside winter residential wood burning. The Loire valley's topographic enclosure can concentrate emissions under calm anticyclonic conditions, while the Massif Central plateau provides clean air on most westerly and northwesterly wind days above the enclosed basin floor.
Today - 9 August | Pollution peaks at 16:00
AQI:
Fair
33.2/100
PM2.5 (fine particles):
Good
7.0/100
PM10 (coarse particles):
Good
2.2/100
NO2 (nitrogen dioxide):
Good
15.5/100
O3 (ozone):
Fair
33.2/100
SO2 (sulfur dioxide):
Good
1.4/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
13.2/100
PM1 (ultrafine particles):
Good
8.6/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 16:00
AQI:
Medium
40.2/100
PM2.5 (fine particles):
Good
8.1/100
PM10 (coarse particles):
Good
4.1/100
NO2 (nitrogen dioxide):
Good
16.7/100
O3 (ozone):
Medium
40.2/100
SO2 (sulfur dioxide):
Good
0.9/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
8.7/100
PM1 (ultrafine particles):
Good
10.2/100
Pollen forecast in Saint-Étienne
View pollen forecastSports venues in Saint-Étienne
Frequently Asked Questions
Is air quality bad in Saint-Étienne right now?
On 9 August 2026, overall air quality in Saint-Étienne is fair. AQI is the main air quality indicator at 33.2/100. Pollution peaks around 4:00 PM (O3: 33.2/100).
Will air quality be worse tomorrow in Saint-Étienne?
On 10 August 2026, air quality conditions in Saint-Étienne will be better than today, with AQI forecast at medium at 40.2/100. Pollution peaks around 4:00 PM (O3: 40.2/100).
When is air pollution at its worst in Saint-Étienne?
Residents in Saint-Étienne tend to notice the most discomfort when valley motorway traffic and light industry build up alongside the spring peak in birch and oak pollen; mountain valley winds alternate with calm temperature inversions, which typically keeps things from getting worse for long.
Are air quality levels in Saint-Étienne based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
Want to see air quality forecasts for other cities in France?
Check air quality in other popular cities:
Data provided by Airmine — Last update: 9 August 2026 at 20:27 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Get the full experience in the Airmine app.