Worst air pollution Herisau, today and tomorrow

Today (16 July): Air quality in Herisau is fair. O3 and PM1 are fair; AQI and NO2 are medium; PM2.5, PM10, SO2, CO, and HCHO are good. Pollution peaks around 4:00 AM (NO2: 45.4/100).
Tomorrow (17 July 2026): Air quality in Herisau is fair. PM2.5 increases to fair; all other pollutants stay as today. Pollution peaks around 1:00 AM (NO2: 52.4/100). Airmine updates local air quality forecasts four times daily.

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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

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Herisau's air quality benefits from its Appenzell foothill position, with vehicle traffic on regional roads the primary local source amid the generally clean, forested pre-Alpine terrain of Appenzell Ausserrhoden.

Today - 16 July | Pollution peaks at 04:00

AQI:

Medium

45.4/100

PM2.5 (fine particles):

Good

17.2/100

PM10 (coarse particles):

Good

6.7/100

NO2 (nitrogen dioxide):

Medium

45.4/100

O3 (ozone):

Fair

39.7/100

SO2 (sulfur dioxide):

Good

2.0/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

5.3/100

PM1 (ultrafine particles):

Fair

21.8/100

Levels show the poorest local air quality during the day

Tomorrow - 17 July | Pollution peaks at 01:00

AQI:

Medium

52.4/100

PM2.5 (fine particles):

Fair

21.2/100

PM10 (coarse particles):

Good

7.8/100

NO2 (nitrogen dioxide):

Medium

52.4/100

O3 (ozone):

Fair

33.9/100

SO2 (sulfur dioxide):

Good

3.3/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

6.0/100

PM1 (ultrafine particles):

Fair

23.5/100

Pollen forecast in Herisau

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Frequently Asked Questions

Is air quality bad in Herisau right now?

On 16 July 2026, overall air quality in Herisau is fair. O3 is the main pollutant at 39.7/100. Pollution peaks around 4:00 AM (NO2: 45.4/100).

Will air quality be worse tomorrow in Herisau?

On 17 July 2026, air quality conditions in Herisau will be similar to today, with O3 forecast at fair at 33.9/100. Pollution peaks around 1:00 AM (NO2: 52.4/100).

When is air pollution at its worst in Herisau?

Herisau's poorest air quality tends to show up when winter stillness lets vehicle traffic and light industry build up in the surrounding valley rather than dispersing. Once spring arrives, dispersion improves steadily along the valley floor, and summer stays largely clear except during rare heatwaves; autumn tends to be comparatively mild.

Are air quality levels in Herisau 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.

Want to see air quality forecasts for other cities in Switzerland?

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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.

For long term forecasts and maps, see the Airmine app