Worst air pollution Valongo, today and tomorrow
Today (21 July): Air quality in Valongo 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 Valongo 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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Valongo's air quality reflects the greater Porto metropolitan area's northern industrial corridor, with vehicle traffic on the A4 motorway and surrounding industrial and logistics character contributing elevated NOₓ and PM2.5. Atlantic westerlies generally provide maritime ventilation through the Porto metropolitan corridor, while the surrounding Valongo hills create topographic variation and the industrial character keeps Valongo among the more emissions-intensive municipalities in greater Porto.
Today - 21 July | Pollution peaks at 14:00
AQI:
Medium
40.1/100
PM2.5 (fine particles):
Good
15.9/100
PM10 (coarse particles):
Good
12.8/100
NO2 (nitrogen dioxide):
Good
10.1/100
O3 (ozone):
Medium
40.1/100
SO2 (sulfur dioxide):
Good
0.7/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
7.3/100
PM1 (ultrafine particles):
Good
14.0/100
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
14.2/100
PM10 (coarse particles):
Good
10.6/100
NO2 (nitrogen dioxide):
Good
11.0/100
O3 (ozone):
Fair
39.9/100
SO2 (sulfur dioxide):
Good
0.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
5.3/100
PM1 (ultrafine particles):
Good
9.4/100
Pollen forecast in Valongo
View pollen forecastFrequently Asked Questions
Is air quality bad in Valongo right now?
On 21 July 2026, overall air quality in Valongo 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 Valongo?
On 22 July 2026, air quality conditions in Valongo 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 Valongo?
The most noticeable dips in Valongo's air quality come when oak and eucalyptus pollen peaks, or because of vehicle traffic on the A4 motorway and nearby industrial and logistics character; wind and rain both help clear the air fairly quickly here.
Are air quality levels in Valongo 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