Heerlen Seasonal Pollution
Heerlen usually records its highest OpenAQ-derived EPA AQI in January and its cleanest month in April. The page uses OpenAQ-derived daily history for 2 mapped monitoring locations in Limburg, Netherlands.
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Average EPA AQI
35
Rank 45 of 71 cities by average AQI
PM2.5
7.1
ug/m3 annualized city average
Seasonality
January
Cleanest: April
Health indicator
0.3
cigarette-equivalent per day
Yearly EPA AQI trend
Seasonal EPA AQI heatmap
JanFebMarAprMayJunJulAugSepOctNovDec
Heerlen
45
25
30
20
37
39
30
40
37
33
44
38
What this seasonality page measures
Find each city's worst and cleanest months from daily OpenAQ-derived EPA AQI.
For Heerlen, the current global analytics build covers 362 daily rows from 2024-01-03 to 2024-12-31. The calculations normalize PM2.5 and PM10 observations into US EPA AQI bands so country, city, and tool pages use one consistent method.