What is the air quality in Oeiras?

Oeiras, Portugal has an annual US AQI of 50 (Reasonable) and average PM2.5 of 9.7 µg/m³, ranking #739 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Oeiras?

November is typically the cleanest month (AQI 45) and March the most polluted (AQI 53).

Where does Oeiras's air quality data come from?

PM2.5: 1998–2026 (satellite 1998–2024, model 2025–2026). From satellite data, because no government monitor covers the city. Full sources are on the methodology page.

Oeiras, Portugal — Air Quality & Clean City Guide 2026

Oeiras Air Quality Data

Global rank	City	Continent	AQI	PM2.5
739	Oeiras, Portugal	Europe	AQI 50	PM2.5 9.7 µg/m³