Belfort vs Saint-Denis AQI Comparison

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

Lower average AQI: Belfort (42-pt gap)PM2.5: Belfort 12.3 ug/m3 · Saint-Denis 13.9 ug/m3

Source: OpenAQ local exports mapped to AQI Now cities; city summaries cover 2024-01-02–2024-12-30 and 2024-01-02–2024-12-30.

Compare two cities

City A

City B

Belfort vs Saint-Denis

Belfort

Bourgogne-Franche-Comté, France

PM2.5: 12.3 ug/m3
PM10: 12.1 ug/m3
Worst month: December
Trend: n/a

EPA category: Good

Saint-Denis

Ile-de-France, France

PM2.5: 13.9 ug/m3
PM10: 28.5 ug/m3
Worst month: December
Trend: n/a

EPA category: Moderate

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

Yearly EPA AQI trend

Seasonal EPA AQI heatmap

JanFebMarAprMayJunJulAugSepOctNovDec

Belfort

Saint-Denis

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.