Aachen Seasonal Pollution
Aachen usually records its highest OpenAQ-derived EPA AQI in January and its cleanest month in September. The page uses OpenAQ-derived daily history for 3 mapped monitoring locations in North Rhine-Westphalia, Germany.
Search city analytics
Average EPA AQI
35
Rank 213 of 297 cities by average AQI
PM2.5
7.5
ug/m3 annualized city average
Seasonality
January
Cleanest: September
Health indicator
0.3
cigarette-equivalent per day
Yearly EPA AQI trend
Seasonal EPA AQI heatmap
JanFebMarAprMayJunJulAugSepOctNovDec
Aachen
46
27
37
27
41
40
30
37
24
33
43
34
What this seasonality page measures
Find each city's worst and cleanest months from daily OpenAQ-derived EPA AQI.
For Aachen, the current global analytics build covers 341 daily rows from 2024-01-01 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.