What is the air quality in Guelph?

Guelph, Canada has an annual US AQI of 43 (Reasonable) and average PM2.5 of 7.7 µg/m³, ranking #358 of 5856 cities. Main pollutant: PM2.5.

What is the cleanest month in Guelph?

October is typically the cleanest month (AQI 35) and July the most polluted (AQI 51).

Where does Guelph's air quality data come from?

PM2.5: 1998–2026 (monitors 2000–2026, satellite 1998–2000; 2025–2026 provisional). Measured by government monitoring stations. Full sources are on the methodology page.

Guelph, Canada — Air Quality & Clean City Guide 2026

Guelph Air Quality Data

Global rank	City	Continent	AQI	PM2.5
358	Guelph, Canada	North America	AQI 43	PM2.5 7.7 µg/m³