SmogRank / World / Europe / Belgium / Wallonia

Most polluted cities in Wallonia, Belgium

17 measured cities, this year; 8 above the WHO annual guideline. Worst: Liège at 7.2 µg/m³, #2,131 in the world.

About 2.27K people in these 3 cities breathed unhealthy air on an average day so far this year.

Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.

Flanders: 27 measured citiesWallonia: 17 measured citiesBrussels Capital: 1 measured city#17 Habay-la-Vieille: 3.7 µg/m³#13 Vielsalm: 4.2 µg/m³#14 Couvin: 4.2 µg/m³#15 Bertrix: 4.2 µg/m³#16 Bastogne: 4.2 µg/m³#12 Eupen: 4.4 µg/m³#11 Ans: 4.5 µg/m³#10 Hamois: 4.7 µg/m³#9 Jumet: 4.8 µg/m³#8 Champion: 5.4 µg/m³#6 Tournai: 5.5 µg/m³#7 Namur: 5.5 µg/m³#4 Rixensart: 5.9 µg/m³#5 Charleroi: 5.9 µg/m³#3 Flémalle-Haute: 6.2 µg/m³#2 Mons: 7.1 µg/m³#1 Liège: 7.2 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Charleroi 1.53K 1K0
Every measured city in Wallonia, Belgium with monitors in two or more places, one column each, ranked by people breathing unhealthy air: height is people on an average day, colour its average. Point at it to read a city; tap to open it.
  1. 1Charleroi 1.53K
  2. 2Liège 743
  3. 3Flémalle-Haute 0
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Estimated: cities without a monitor

Wallonia cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
La Louvière≈ 7 µg/m³Good
Seraing≈ 6 µg/m³Good
Verviers≈ 6 µg/m³Good
Mouscron≈ 10 µg/m³Moderate
Braine-l'Alleud≈ 8 µg/m³Good
Herstal≈ 8 µg/m³Good
Châtelet≈ 7 µg/m³Good
Wavre≈ 8 µg/m³Good
Binche≈ 7 µg/m³Good
Waterloo≈ 8 µg/m³Good
Louvain-la-Neuve≈ 8 µg/m³Good
Courcelles≈ 7 µg/m³Good
Ath≈ 8 µg/m³Good
Arlon≈ 8 µg/m³Good
Soignies≈ 7 µg/m³Good
Nivelles≈ 7 µg/m³Good
Andenne≈ 6 µg/m³Good
Marcinelle≈ 7 µg/m³Good
Oupeye≈ 8 µg/m³Good
Saint-Nicolas≈ 8 µg/m³Good
Saint-Ghislain≈ 8 µg/m³Good
Manage≈ 7 µg/m³Good
Fleurus≈ 7 µg/m³Good
Gembloux≈ 7 µg/m³Good
Grivegnée≈ 8 µg/m³Good
Chaudfontaine≈ 6 µg/m³Good
Frameries≈ 7 µg/m³Good
Braine-le-Comte≈ 8 µg/m³Good
Boussu≈ 8 µg/m³Good
Gilly≈ 7 µg/m³Good
Huy≈ 6 µg/m³Good
Colfontaine≈ 7 µg/m³Good
Jambes≈ 6 µg/m³Good
Montignies-sur-Sambre≈ 7 µg/m³Good
Quaregnon≈ 7 µg/m³Good
Morlanwelz-Mariemont≈ 7 µg/m³Good
Tubize≈ 8 µg/m³Good
Lessines≈ 8 µg/m³Good
Walcourt≈ 7 µg/m³Good
Châtelineau≈ 7 µg/m³Good

Bad-air episodes in Wallonia

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

Use this board

SmogRank, most polluted cities in Wallonia, Belgium, PM2.5, this year to 6 Oct 2026, 22:00 UTC, smogrank.com/be/region/wallonia?w=year.

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.