Worst air pollution Santarém, today and tomorrow
Today (21 July): Air quality in Santarém is fair. AQI, NO2, and O3 are fair; PM2.5, PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 10:00 PM (O3: 37.0/100).
Tomorrow (22 July 2026): Air quality in Santarém is fair. NO2 decreases to good; all other pollutants stay as today. Pollution peaks around 8:00 PM (O3: 36.2/100). 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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Santarém's air quality in Portugal benefits from the flat Ribatejo plain position on the Tagus valley, with consistent Atlantic westerlies channelled through the Tagus corridor providing reliable ventilation across this historic hilltop agricultural city. Vehicle traffic on the A1 motorway and surrounding agri-food and agricultural industry contribute local sources, while the Tagus valley's open geometry and Atlantic estuary ventilation generally maintain Santarém among Portugal's more moderate central regional capital environments throughout most of the year.
Today - 21 July | Pollution peaks at 22:00
AQI:
Fair
37.0/100
PM2.5 (fine particles):
Good
11.8/100
PM10 (coarse particles):
Good
7.4/100
NO2 (nitrogen dioxide):
Fair
27.6/100
O3 (ozone):
Fair
37.0/100
SO2 (sulfur dioxide):
Good
4.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.7/100
PM1 (ultrafine particles):
Good
7.6/100
Levels show the poorest local air quality during the day
Tomorrow - 22 July | Pollution peaks at 20:00
AQI:
Fair
36.2/100
PM2.5 (fine particles):
Good
16.7/100
PM10 (coarse particles):
Good
12.0/100
NO2 (nitrogen dioxide):
Good
15.2/100
O3 (ozone):
Fair
36.2/100
SO2 (sulfur dioxide):
Good
3.7/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
1.8/100
PM1 (ultrafine particles):
Good
10.9/100
Pollen forecast in Santarém
View pollen forecastFrequently Asked Questions
Is air quality bad in Santarém right now?
On 21 July 2026, overall air quality in Santarém is fair. AQI is the main air quality indicator at 37.0/100. Pollution peaks around 10:00 PM (O3: 37.0/100).
Will air quality be worse tomorrow in Santarém?
On 22 July 2026, air quality conditions in Santarém will be similar to today, with AQI forecast at fair at 36.2/100. Pollution peaks around 8:00 PM (O3: 36.2/100).
When is air pollution at its worst in Santarém?
You're likeliest to notice worse air in Santarém when floodplain oak and eucalyptus pollen peaks, or due to vehicle traffic on the A1 motorway and surrounding agri-food and agricultural industry; for the rest of the year, natural airflow keeps background levels low.
Are air quality levels in Santarém 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