Worst air pollution Herstal, today and tomorrow
Today (9 August): Air quality in Herstal is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 52.1/100).
Tomorrow (10 August 2026): Air quality in Herstal is fair. AQI worsens to fair; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 3:00 PM (O3: 35.2/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Herstal's air quality reflects its position on the Meuse river plain near Liège, with industrial emissions and vehicle traffic in the river valley contributing the main local sources through the year. Weather patterns typical of Liège shape how quickly pollutants clear, with conditions generally improving whenever winds pick up or rain moves through, while calmer, high-pressure spells tend to let local emissions accumulate for longer than elsewhere in the region.
Today - 9 August | Pollution peaks at 13:00
AQI:
Medium
52.1/100
PM2.5 (fine particles):
Good
8.9/100
PM10 (coarse particles):
Good
3.2/100
NO2 (nitrogen dioxide):
Good
2.0/100
O3 (ozone):
Medium
52.1/100
SO2 (sulfur dioxide):
Good
0.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
8.8/100
PM1 (ultrafine particles):
Good
12.4/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 15:00
AQI:
Fair
35.2/100
PM2.5 (fine particles):
Good
7.1/100
PM10 (coarse particles):
Good
2.9/100
NO2 (nitrogen dioxide):
Good
1.0/100
O3 (ozone):
Fair
35.2/100
SO2 (sulfur dioxide):
Good
0.2/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
8.1/100
PM1 (ultrafine particles):
Good
8.2/100
Pollen forecast in Herstal
View pollen forecastFrequently Asked Questions
Is air quality bad in Herstal right now?
On 9 August 2026, overall air quality in Herstal is medium. AQI is the main air quality indicator at 52.1/100. Pollution peaks around 1:00 PM (O3: 52.1/100).
Will air quality be worse tomorrow in Herstal?
On 10 August 2026, air quality conditions in Herstal will be worse than today, with AQI forecast at fair at 35.2/100. Pollution peaks around 3:00 PM (O3: 35.2/100).
When is air pollution at its worst in Herstal?
In Herstal, reduced air quality is most noticeable when oak and hornbeam pollen is at its peak, and on days affected by industrial emissions and vehicle traffic in the river valley; conditions tend to settle down again once weather patterns shift and the local Liège terrain ventilates more freely, usually bringing several weeks of steadier readings.
Are air quality levels in Herstal based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 9 August 2026 at 20:27 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
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