What is the air quality in Longueuil?

Longueuil, Canada has an annual US AQI of 46 (Reasonable) and average PM2.5 of 8.6 µg/m³, ranking #495 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Longueuil?

October is typically the cleanest month (AQI 36) and January the most polluted (AQI 52).

Where does Longueuil's air quality data come from?

PM2.5: 1998–2026 (monitors 2003–2026, satellite 1998–2003, 2008; 2025–2026 provisional). Measured by government monitoring stations. Full sources are on the methodology page.

Longueuil, Canada — Air Quality & Clean City Guide 2026

Longueuil Air Quality Data

Global rank	City	Continent	AQI	PM2.5
495	Longueuil, Canada	North America	AQI 46	PM2.5 8.6 µg/m³