What is the air quality in Sintra?

Sintra, Portugal has an annual US AQI of 50 (Reasonable) and average PM2.5 of 9.5 µg/m³, ranking #728 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Sintra?

April is typically the cleanest month (AQI 47) and January the most polluted (AQI 55).

Where does Sintra's air quality data come from?

PM2.5: 1998–2026 (monitors 2013–2026, satellite 1998–2014; 2026 provisional). Measured by government monitoring stations. Full sources are on the methodology page.

Sintra, Portugal — Air Quality & Clean City Guide 2026

Sintra Air Quality Data

Global rank	City	Continent	AQI	PM2.5
728	Sintra, Portugal	Europe	AQI 50	PM2.5 9.5 µg/m³