Koper vs Postojna AQI Comparison

Side-by-side OpenAQ-derived air quality comparison for Koper and Postojna. Values use mapped daily PM2.5 and PM10 observations normalized to US EPA AQI.

Lower average AQI: Koper (16-pt gap)PM2.5: Koper 9.9 ug/m3 · Postojna 11.0 ug/m3

Source: OpenAQ local exports mapped to AQI Now cities; city summaries cover 2024-01-03–2024-12-31 and 2024-07-31–2024-12-31.

Compare two cities

City A

City B

Koper vs Postojna

Koper

Koper, Slovenia

PM2.5: 9.9 ug/m3
PM10: 17.2 ug/m3
Worst month: November
Trend: n/a

EPA category: Good

Postojna

Postojna, Slovenia

PM2.5: 11.0 ug/m3
PM10: n/a ug/m3
Worst month: November
Trend: n/a

EPA category: Good

Lower average AQI in this selected period: Koper. Values are historical OpenAQ-derived city summaries, not live readings.

Yearly EPA AQI trend

Seasonal EPA AQI heatmap

JanFebMarAprMayJunJulAugSepOctNovDec

Koper

Postojna

What this comparison measures

Average EPA AQI — city-level daily AQI values averaged across the OpenAQ coverage window.
PM2.5 and PM10 — mapped monitor concentrations aggregated to daily city averages.
Seasonality — worst and cleanest months from the monthly city rollups.
Trend — difference between the earliest and latest yearly AQI average in this build.