Worst air pollution Castle of Good Hope - Cape Town, today and tomorrow
Today (21 September): Air quality in Castle of Good Hope is poor. AQI and PM1 are poor; PM2.5, PM10, and SO2 are moderate; NO2, O3, and HCHO are fair; CO is good. Pollution peaks around 11:00 PM (PM1: 65.8/100).
Tomorrow (22 September 2026): Air quality in Castle of Good Hope is very poor. AQI worsens to very poor; PM10 increases to poor; NO2 increases to moderate; O3 increases to poor; HCHO increases to moderate; PM1 increases to very poor; all other pollutants stay as today. Pollution peaks around 9:00 PM (PM1: 100/100). Airmine updates local air quality forecasts four times daily.
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Vehicle traffic and the city bowl, harbour, and southern suburbs are the main local sources shaping air quality at Castle of Good Hope, though the Cape's reliably windy climate generally disperses pollution quickly. Winter mornings occasionally see calmer conditions that briefly allow emissions to linger near the ground. Much of the surrounding Cape sees broadly the same seasonal pattern.
Today - 21 September | Pollution peaks at 23:00
AQI:
Poor
65.8/100
PM2.5 (fine particles):
Moderate
40.7/100
PM10 (coarse particles):
Moderate
40.4/100
NO2 (nitrogen dioxide):
Fair
27.7/100
O3 (ozone):
Fair
29.8/100
SO2 (sulfur dioxide):
Moderate
41.1/100
CO (carbon monoxide):
Good
2.6/100
HCHO (formaldehyde):
Fair
31.9/100
PM1 (ultrafine particles):
Poor
65.8/100
Levels show the poorest local air quality during the day
Tomorrow - 22 September | Pollution peaks at 21:00
AQI:
Very poor
100/100
PM2.5 (fine particles):
Moderate
58.5/100
PM10 (coarse particles):
Poor
66.1/100
NO2 (nitrogen dioxide):
Moderate
46.0/100
O3 (ozone):
Poor
79.1/100
SO2 (sulfur dioxide):
Moderate
56.2/100
CO (carbon monoxide):
Good
5.4/100
HCHO (formaldehyde):
Moderate
50.5/100
PM1 (ultrafine particles):
Very poor
100/100
Other Landmarks in Cape Town
Sports venues in Cape Town
Frequently Asked Questions
Is air quality bad in Castle of Good Hope right now?
On 21 September 2026, overall air quality in Castle of Good Hope is poor. AQI is the main air quality indicator at 65.8/100. Pollution peaks around 11:00 PM (PM1: 65.8/100).
Will air quality be worse tomorrow in Castle of Good Hope?
On 22 September 2026, air quality conditions in Castle of Good Hope will be worse than today, with AQI forecast at very poor at 100/100. Pollution peaks around 9:00 PM (PM1: 100/100).
When is air pollution at its worst in Castle of Good Hope?
The only real dip in air quality at Castle of Good Hope comes on the rare still winter morning, when the Cape's usual wind stops doing its job and emissions from the city bowl, harbour, and southern suburbs linger a little longer than usual. Most of the year, especially summer, the southeaster keeps things clear. This is a familiar pattern across much of the Cape.
Are air quality levels in Castle of Good Hope 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: 21 September 2026 at 08:52 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.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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