Montréal Seasonal Pollution
Montréal usually records its highest OpenAQ-derived EPA AQI in August and its cleanest month in November. The page uses OpenAQ-derived daily history for 2 mapped monitoring locations in Quebec, Canada.
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Average EPA AQI
34
Rank 51 of 158 cities by average AQI
PM2.5
7.0
ug/m3 annualized city average
Seasonality
August
Cleanest: November
Health indicator
0.3
cigarette-equivalent per day
Yearly EPA AQI trend
Seasonal EPA AQI heatmap
JanFebMarAprMayJunJulAugSepOctNovDec
Montréal
33
39
29
24
33
38
43
47
38
29
23
39
What this seasonality page measures
Find each city's worst and cleanest months from daily OpenAQ-derived EPA AQI.
For Montréal, the current global analytics build covers 365 daily rows from 2024-01-01 to 2025-01-01. The calculations normalize PM2.5 and PM10 observations into US EPA AQI bands so country, city, and tool pages use one consistent method.