Worst air pollution Guimarães, today and tomorrow

Today (21 July): Air quality in Guimarães is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 3:00 PM (O3: 43.5/100).
Tomorrow (22 July 2026): Air quality in Guimarães is medium. All pollutants stay as today. Pollution peaks around 5:00 PM (O3: 40.9/100). 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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Guimarães' air quality benefits from its Atlantic position in the Minho region of northwestern Portugal, with consistent Atlantic westerlies providing reliable maritime ventilation across this UNESCO heritage textile and technology city. Vehicle traffic on the A11 and the surrounding leather, textile, and cutlery manufacturing industry contribute the primary local emissions, while the surrounding Peneda-Gerês mountains provide a clean-air backdrop and the Atlantic coastal proximity generally keeps Guimarães among Portugal's more moderate urban air quality environments throughout the year.

Today - 21 July | Pollution peaks at 15:00

AQI:

Medium

43.5/100

PM2.5 (fine particles):

Good

13.7/100

PM10 (coarse particles):

Good

8.1/100

NO2 (nitrogen dioxide):

Good

19.4/100

O3 (ozone):

Medium

43.5/100

SO2 (sulfur dioxide):

Good

1.1/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

6.8/100

PM1 (ultrafine particles):

Good

11.2/100

Levels show the poorest local air quality during the day

Tomorrow - 22 July | Pollution peaks at 17:00

AQI:

Medium

40.9/100

PM2.5 (fine particles):

Good

14.4/100

PM10 (coarse particles):

Good

10.3/100

NO2 (nitrogen dioxide):

Good

10.0/100

O3 (ozone):

Medium

40.9/100

SO2 (sulfur dioxide):

Good

1.5/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

4.2/100

PM1 (ultrafine particles):

Good

10.3/100

Pollen forecast in Guimarães

View pollen forecast

Frequently Asked Questions

Is air quality bad in Guimarães right now?

On 21 July 2026, overall air quality in Guimarães is medium. AQI is the main air quality indicator at 43.5/100. Pollution peaks around 3:00 PM (O3: 43.5/100).

Will air quality be worse tomorrow in Guimarães?

On 22 July 2026, air quality conditions in Guimarães will be similar to today, with AQI forecast at medium at 40.9/100. Pollution peaks around 5:00 PM (O3: 40.9/100).

When is air pollution at its worst in Guimarães?

Reduced air quality in Guimarães is most likely when pine and eucalyptus pollen peaks, alongside periods of vehicle traffic on the A11 and the neighbouring leather, textile, and cutlery manufacturing industry; outside of those periods, conditions here remain among the more favourable in the region.

Are air quality levels in Guimarães 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 Portugal?

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Data provided by Airmine — Last update: 21 July 2026 at 16:20 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