Worst air pollution Sintra hills - Lisbon, today and tomorrow

Today (30 August): Air quality in Sintra hills is moderate. AQI and O3 are moderate; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 41.2/100).
Tomorrow (31 August 2026): Air quality in Sintra hills is fair. AQI improves to fair; O3 decreases to fair; all other pollutants stay as today. Pollution peaks around 1:00 PM (O3: 32.3/100). 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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Lisbon's Sintra hills record excellent air quality on the UNESCO-listed ridge above the Atlantic plain northwest of Lisbon, with consistent Atlantic Ocean airflows providing outstanding clean maritime ventilation throughout the year. This is consistently one of the cleanest locations in the greater Lisbon region, with readings approaching open ocean coastal values on most days.

Today - 30 August | Pollution peaks at 13:00

AQI:

Moderate

41.2/100

PM2.5 (fine particles):

Good

10.2/100

PM10 (coarse particles):

Good

9.6/100

NO2 (nitrogen dioxide):

Good

10.4/100

O3 (ozone):

Moderate

41.2/100

SO2 (sulfur dioxide):

Good

1.6/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

6.8/100

PM1 (ultrafine particles):

Good

6.5/100

Levels show the poorest local air quality during the day

Tomorrow - 31 August | Pollution peaks at 13:00

AQI:

Fair

32.3/100

PM2.5 (fine particles):

Good

12.3/100

PM10 (coarse particles):

Good

10.6/100

NO2 (nitrogen dioxide):

Good

8.0/100

O3 (ozone):

Fair

32.3/100

SO2 (sulfur dioxide):

Good

1.6/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

6.7/100

PM1 (ultrafine particles):

Good

6.4/100

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Frequently Asked Questions

Is air quality bad in Sintra hills right now?

On 30 August 2026, overall air quality in Sintra hills is moderate. AQI is the main air quality indicator at 41.2/100. Pollution peaks around 1:00 PM (O3: 41.2/100).

Will air quality be worse tomorrow in Sintra hills?

On 31 August 2026, air quality conditions in Sintra hills will be better than today, with AQI forecast at fair at 32.3/100. Pollution peaks around 1:00 PM (O3: 32.3/100).

When is air pollution at its worst in Sintra hills?

People in Sintra hills tend to notice reduced air quality when local combined tree and grass pollen peaks, or because of this is consistently one of the cleanest locations in the greater Lisbon region, with; outside those spells, this remains one of the more consistently clean-air places to be.

Are air quality levels in Sintra hills 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: 30 August 2026 at 20:26 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.

Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.

Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.

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