Worst air pollution Hornlee - Knysna, today and tomorrow
Today (9 August): Air quality in Hornlee is good. AQI, PM2.5, PM10, NO2, O3, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 8:00 PM (O3: 16.0/100).
Tomorrow (10 August 2026): Air quality in Hornlee is good. All pollutants stay as today. Pollution peaks around 3:00 PM (O3: 17.5/100). 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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Hornlee lies roughly 420 km east of Cape Town. Vehicle traffic and tourism and forestry operations are the main local sources affecting air quality at Hornlee, though the Garden Route's consistent onshore wind and rainfall generally keep conditions favourable. Only rare still days interrupt what is typically a well-ventilated coastal climate. Much of the surrounding Garden Route sees broadly the same pattern.
Today - 9 August | Pollution peaks at 20:00
AQI:
Good
16.0/100
PM2.5 (fine particles):
Good
4.1/100
PM10 (coarse particles):
Good
1.6/100
NO2 (nitrogen dioxide):
Good
0/100
O3 (ozone):
Good
16.0/100
SO2 (sulfur dioxide):
Good
0/100
CO (carbon monoxide):
Good
0/100
HCHO (formaldehyde):
Good
1.2/100
PM1 (ultrafine particles):
Good
2.3/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 15:00
AQI:
Good
17.5/100
PM2.5 (fine particles):
Good
3.4/100
PM10 (coarse particles):
Good
1.5/100
NO2 (nitrogen dioxide):
Good
0/100
O3 (ozone):
Good
17.5/100
SO2 (sulfur dioxide):
Good
0/100
CO (carbon monoxide):
Good
0/100
HCHO (formaldehyde):
Good
0.6/100
PM1 (ultrafine particles):
Good
1.2/100
Other Landmarks in Knysna
Sports venues in Knysna
Frequently Asked Questions
Is air quality bad in Hornlee right now?
On 9 August 2026, overall air quality in Hornlee is good. AQI is the main air quality indicator at 16.0/100. Pollution peaks around 8:00 PM (O3: 16.0/100).
Will air quality be worse tomorrow in Hornlee?
On 10 August 2026, air quality conditions in Hornlee will be similar to today, with AQI forecast at good at 17.5/100. Pollution peaks around 3:00 PM (O3: 17.5/100).
When is air pollution at its worst in Hornlee?
Air quality at Hornlee stays fairly consistent throughout the year thanks to steady onshore breezes, with only occasional dips on rare still days when emissions from tourism and forestry operations briefly build up. Conditions typically clear again within a day as the sea breeze reasserts itself, a seasonal pattern typical of the wider Garden Route coastline.
Are air quality levels in Hornlee 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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