Worst air pollution Brno, today and tomorrow

Today (20 September): Air quality in Brno is fair. AQI, PM2.5, PM10, NO2, and PM1 are fair; O3, SO2, CO, and HCHO are good. Pollution peaks around 7:00 AM (PM2.5: 36.5/100).
Tomorrow (21 September 2026): Air quality in Brno is good. AQI improves to good; PM2.5 decreases to good; PM10 decreases to good; NO2 decreases to good; PM1 decreases to good; all other pollutants stay as today. Pollution peaks around 4:00 PM (O3: 12.6/100). 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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Brno's air quality reflects its position in the South Moravian basin, with vehicle traffic on the D1 and D2 motorway interchange and the surrounding manufacturing industry contributing elevated NO₂ and PM2.5. The Bohemian-Moravian Highlands to the northwest provide partial topographic shelter, while winter residential wood and coal burning adds seasonal PM2.5 in this second-largest Czech city. Atlantic westerlies generally provide reasonable ventilation on most wind days.

Today - 20 September | Pollution peaks at 07:00

AQI:

Fair

36.5/100

PM2.5 (fine particles):

Fair

36.5/100

PM10 (coarse particles):

Fair

21.6/100

NO2 (nitrogen dioxide):

Fair

35.2/100

O3 (ozone):

Good

17.0/100

SO2 (sulfur dioxide):

Good

1.7/100

CO (carbon monoxide):

Good

1.3/100

HCHO (formaldehyde):

Good

3.9/100

PM1 (ultrafine particles):

Fair

27.7/100

Levels show the poorest local air quality during the day

Tomorrow - 21 September | Pollution peaks at 16:00

AQI:

Good

12.6/100

PM2.5 (fine particles):

Good

12.3/100

PM10 (coarse particles):

Good

9.3/100

NO2 (nitrogen dioxide):

Good

10.0/100

O3 (ozone):

Good

12.6/100

SO2 (sulfur dioxide):

Good

1.1/100

CO (carbon monoxide):

Good

0.7/100

HCHO (formaldehyde):

Good

1.9/100

PM1 (ultrafine particles):

Good

4.8/100

Pollen forecast in Brno

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Frequently Asked Questions

Is air quality bad in Brno right now?

On 20 September 2026, overall air quality in Brno is fair. AQI is the main air quality indicator at 36.5/100. Pollution peaks around 7:00 AM (PM2.5: 36.5/100).

Will air quality be worse tomorrow in Brno?

On 21 September 2026, air quality conditions in Brno will be better than today, with AQI forecast at good at 12.6/100. Pollution peaks around 4:00 PM (O3: 12.6/100).

When is air pollution at its worst in Brno?

Reduced air quality in Brno is most likely when birch and oak peaks pollen peaks, alongside periods of vehicle traffic on the D1 and D2 motorway interchange and the neighbouring manufacturing industry; background levels usually settle back down once the season changes.

Are air quality levels in Brno 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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