Worst air pollution Sankt Gallen, today and tomorrow
Today (20 September): Air quality in Sankt Gallen is moderate. AQI and NO2 are moderate; PM2.5, PM10, O3, and PM1 are fair; SO2, CO, and HCHO are good. Pollution peaks around 8:00 AM (NO2: 40.0/100).
Tomorrow (21 September 2026): Air quality in Sankt Gallen is fair. AQI improves to fair; PM2.5 decreases to good; PM10 decreases to good; NO2 decreases to fair; PM1 decreases to good; all other pollutants stay as today. Pollution peaks around 6:00 PM (O3: 23.4/100). Airmine updates local air quality forecasts four times daily.
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Sankt Gallen's air quality reflects the Swiss Rhine valley position in the Appenzell foothills, with vehicle traffic on the A1 motorway and the surrounding textile machinery and precision manufacturing industry contributing local sources. The surrounding Swiss Alpine foothills create topographic variation, while the Rhine valley provides the primary ventilation corridor on westerly winds and the Alpine Föhn periodically delivers clean mountain air from the south throughout the year.
Today - 20 September | Pollution peaks at 08:00
AQI:
Moderate
40.0/100
PM2.5 (fine particles):
Fair
29.4/100
PM10 (coarse particles):
Fair
21.7/100
NO2 (nitrogen dioxide):
Moderate
40.0/100
O3 (ozone):
Fair
34.5/100
SO2 (sulfur dioxide):
Good
0.7/100
CO (carbon monoxide):
Good
0.9/100
HCHO (formaldehyde):
Good
4.4/100
PM1 (ultrafine particles):
Fair
26.4/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 18:00
AQI:
Fair
23.4/100
PM2.5 (fine particles):
Good
17.7/100
PM10 (coarse particles):
Good
15.3/100
NO2 (nitrogen dioxide):
Fair
21.6/100
O3 (ozone):
Fair
23.4/100
SO2 (sulfur dioxide):
Good
0.8/100
CO (carbon monoxide):
Good
0.7/100
HCHO (formaldehyde):
Good
4.1/100
PM1 (ultrafine particles):
Good
11.0/100
Pollen forecast in Sankt Gallen
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Frequently Asked Questions
Is air quality bad in Sankt Gallen right now?
On 20 September 2026, overall air quality in Sankt Gallen is moderate. AQI is the main air quality indicator at 40.0/100. Pollution peaks around 8:00 AM (NO2: 40.0/100).
Will air quality be worse tomorrow in Sankt Gallen?
On 21 September 2026, air quality conditions in Sankt Gallen will be better than today, with AQI forecast at fair at 23.4/100. Pollution peaks around 6:00 PM (O3: 23.4/100).
When is air pollution at its worst in Sankt Gallen?
Calm winter conditions are when Sankt Gallen's air quality suffers most, with vehicle traffic and light industry settling into the valley instead of clearing with the wind as usual. The rest of the year sees much better conditions in this valley, with summer's ozone spikes limited to the hottest, stillest days.
Are air quality levels in Sankt Gallen 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.
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Data provided by Airmine — Last update: 20 September 2026 at 14:33 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.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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