What is the air quality in Cascais?

Cascais, Portugal has an annual US AQI of 49 (Reasonable) and average PM2.5 of 9.1 µg/m³, ranking #647 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Cascais?

November is typically the cleanest month (AQI 43) and March the most polluted (AQI 52).

Where does Cascais'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.

Cascais, Portugal — Air Quality & Clean City Guide 2026

Cascais Air Quality Data

Global rank	City	Continent	AQI	PM2.5
647	Cascais, Portugal	Europe	AQI 49	PM2.5 9.1 µg/m³