Sofia Seasonal Pollution
Sofia usually records its highest OpenAQ-derived EPA AQI in December and its cleanest month in May. The page uses OpenAQ-derived daily history for 3 mapped monitoring locations in Sofia-Grad, Bulgaria.
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Average EPA AQI
31
Rank 23 of 35 cities by average AQI
PM2.5
48.1
ug/m3 annualized city average
Seasonality
December
Cleanest: May
Health indicator
2.2
cigarette-equivalent per day
Yearly EPA AQI trend
Seasonal EPA AQI heatmap
JanFebMarAprMayJunJulAugSepOctNovDec
Sofia
30
27
28
21
17
27
21
20
21
28
29
101
What this seasonality page measures
Find each city's worst and cleanest months from daily OpenAQ-derived EPA AQI.
For Sofia, 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.