Norrtälje Seasonal Pollution
Norrtälje usually records its highest OpenAQ-derived EPA AQI in March and its cleanest month in November. The page uses OpenAQ-derived daily history for 3 mapped monitoring locations in Stockholm, Sweden.
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Average EPA AQI
23
Rank 20 of 31 cities by average AQI
PM2.5
4.3
ug/m3 annualized city average
Seasonality
March
Cleanest: November
Health indicator
0.2
cigarette-equivalent per day
Yearly EPA AQI trend
Seasonal EPA AQI heatmap
JanFebMarAprMayJunJulAugSepOctNovDec
Norrtälje
21
27
40
21
32
28
26
28
18
18
9
13
What this seasonality page measures
Find each city's worst and cleanest months from daily OpenAQ-derived EPA AQI.
For Norrtälje, the current global analytics build covers 326 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.