Worst air pollution Alfama & São Jorge Castle - Lisbon, today and tomorrow
Today (21 July): Air quality in Alfama & São Jorge Castle 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: 42.7/100).
Tomorrow (22 July 2026): Air quality in Alfama & São Jorge Castle is fair. AQI worsens to fair; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 12:00 PM (O3: 33.7/100). 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
Use our Strava plugin to check your own exposure.
Lisbon's Alfama and São Jorge Castle record moderate central Lisbon air quality, with the historic hillside neighbourhood and the castle's elevated position providing slightly better conditions than the dense Baixa below. The Tagus estuary breeze corridor provides periodic ventilation up the hillside, though tourist traffic and narrow lanes limit effective dispersal on calm summer days.
Today - 21 July | Pollution peaks at 15:00
AQI:
Medium
42.7/100
PM2.5 (fine particles):
Good
14.9/100
PM10 (coarse particles):
Good
11.5/100
NO2 (nitrogen dioxide):
Good
11.2/100
O3 (ozone):
Medium
42.7/100
SO2 (sulfur dioxide):
Good
1.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
9.3/100
PM1 (ultrafine particles):
Good
10.0/100
Levels show the poorest local air quality during the day
Tomorrow - 22 July | Pollution peaks at 12:00
AQI:
Fair
33.7/100
PM2.5 (fine particles):
Good
15.4/100
PM10 (coarse particles):
Good
12.7/100
NO2 (nitrogen dioxide):
Good
5.4/100
O3 (ozone):
Fair
33.7/100
SO2 (sulfur dioxide):
Good
1.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
3.2/100
PM1 (ultrafine particles):
Good
10.0/100
Other Landmarks in Lisbon
Sports venues in Lisbon
Frequently Asked Questions
Is air quality bad in Alfama & São Jorge Castle right now?
On 21 July 2026, overall air quality in Alfama & São Jorge Castle is medium. AQI is the main air quality indicator at 42.7/100. Pollution peaks around 3:00 PM (O3: 42.7/100).
Will air quality be worse tomorrow in Alfama & São Jorge Castle?
On 22 July 2026, air quality conditions in Alfama & São Jorge Castle will be worse than today, with AQI forecast at fair at 33.7/100. Pollution peaks around 12:00 PM (O3: 33.7/100).
When is air pollution at its worst in Alfama & São Jorge Castle?
Reduced air quality in Alfama & São Jorge Castle is most likely when olive and introduced ornamental trees pollen peaks, alongside periods of the historic hillside neighbourhood and the castle's; the clearest air tends to follow a change in wind direction or rainfall here.
Are air quality levels in Alfama & São Jorge Castle 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?
Check air quality in other popular cities:
Data provided by Airmine — Last update: 21 July 2026 at 10:44 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