Worst air pollution Maia, today and tomorrow

Today (21 July): Air quality in Maia is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 2:00 PM (O3: 40.1/100).
Tomorrow (22 July 2026): Air quality in Maia is fair. AQI worsens to fair; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 3:00 PM (O3: 39.9/100). Airmine updates local air quality forecasts four times daily.

For long term forecasts and maps, see the Airmine app

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

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Maia's air quality reflects its position in the greater Porto metropolitan area's northern industrial corridor, with vehicle traffic on the A3 and the surrounding logistics, electronics manufacturing, and Porto Airport operations contributing elevated NOₓ and aviation PM2.5 in the flight corridor. Atlantic westerlies generally provide maritime ventilation, while the Porto Airport's proximity makes aviation emissions a distinctive local air quality source, and the industrial character of the northern Porto corridor keeps Maia among the more emissions-intensive municipalities in the greater metropolitan area.

Today - 21 July | Pollution peaks at 14:00

AQI:

Medium

40.1/100

PM2.5 (fine particles):

Good

15.2/100

PM10 (coarse particles):

Good

12.3/100

NO2 (nitrogen dioxide):

Good

7.8/100

O3 (ozone):

Medium

40.1/100

SO2 (sulfur dioxide):

Good

0.5/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

7.3/100

PM1 (ultrafine particles):

Good

13.4/100

Levels show the poorest local air quality during the day

Tomorrow - 22 July | Pollution peaks at 15:00

AQI:

Fair

39.9/100

PM2.5 (fine particles):

Good

13.6/100

PM10 (coarse particles):

Good

10.2/100

NO2 (nitrogen dioxide):

Good

8.5/100

O3 (ozone):

Fair

39.9/100

SO2 (sulfur dioxide):

Good

0.6/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

5.3/100

PM1 (ultrafine particles):

Good

9.0/100

Pollen forecast in Maia

View pollen forecast

Frequently Asked Questions

Is air quality bad in Maia right now?

On 21 July 2026, overall air quality in Maia is medium. AQI is the main air quality indicator at 40.1/100. Pollution peaks around 2:00 PM (O3: 40.1/100).

Will air quality be worse tomorrow in Maia?

On 22 July 2026, air quality conditions in Maia will be worse than today, with AQI forecast at fair at 39.9/100. Pollution peaks around 3:00 PM (O3: 39.9/100).

When is air pollution at its worst in Maia?

You're quickest to notice worse air in Maia when local combined tree and grass pollen peaks, or due to vehicle traffic on the A3 and the neighbouring logistics, electronics manufacturing, and Porto Airport operations; conditions usually ease once the wet season or windier weather returns.

Are air quality levels in Maia 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