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 forecastFrequently 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.
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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