Cape Town Air Quality (AQI)
South Africa · Western Cape · Cape Doctor Winds, Wood Smoke & Industrial Pollution
The Cape Doctor southeaster gives Cape Town excellent natural ventilation in summer (Dec–Feb). In winter, wood smoke from informal settlements creates a two-tier city: clean ocean suburbs vs. heavily polluted Cape Flats townships.
Monthly AQI Pattern
Pollution Sources
| Pollutant | Level | WHO | Sources |
|---|---|---|---|
| PM2.5 | 12–16 μg/m³ (annual) | 5 μg/m³ | Wood/coal burning in informal settlements (Khayelitsha, Mitchell's Plain, Gugulethu) |
| PM10 | 20–35 μg/m³ | 15 μg/m³ | Dust from construction and industrial zones; road dust in informal settlements |
| NO₂ | 18–28 μg/m³ | 10 μg/m³ | N2 highway (Table Bay Boulevard), city traffic, industrial Bellville corridor |
| SO₂ | Low–moderate | 40 μg/m³ | Synfuels Parow, Caltex oil refinery (Milnerton/Paarden Eiland) |
| Ozone (O₃) | Moderate summer | 60 μg/m³ | Vehicle NOx + UV; less severe than inland cities due to sea ventilation |
Air Quality by Area
Table Mountain provides shelter from SE; ocean ventilation; traffic the main source
Ocean exposure on both sides, excellent natural ventilation, minimal industry
Protected by mountain, generally good but traffic congestion on main routes
Large informal settlements with widespread wood/coal burning for heating; densely populated; limited ventilation in winter inversions
Industrial corridor — manufacturing, Caltex refinery nearby, heavy N1 traffic
Caltex refinery proximity; industrial Paarden Eiland; but Atlantic ocean breezes help
Frequently Asked Questions
What is the Cape Doctor and how does it affect Cape Town's air quality?
The 'Cape Doctor' is Cape Town's famous southeaster — a strong, persistent southeasterly wind that blows most strongly from November through March. The wind originates from a high-pressure system over the South Atlantic and funnels through the Cape Peninsula, sometimes reaching gale force (60–80 km/h) with distinctive 'tablecloth' cloud formations over Table Mountain. The Cape Doctor gets its name from its historical reputation for literally 'doctoring' the Cape by blowing away disease and bad air from the city. For air quality, the Cape Doctor is enormously beneficial: it disperses vehicle exhaust, industrial emissions, and smoke from Cape Town within hours of formation. Summer in Cape Town is uniquely clean for an African city of its size precisely because the Cape Doctor is active.
Why is winter air quality poor in Cape Town's informal settlements?
Cape Town's Cape Flats townships — including Khayelitsha, Mitchell's Plain, Gugulethu, Langa, and Crossroads — house an estimated 2–3 million people, many in informal structures with limited insulation. In winter (June–August), temperatures drop to 5–10°C, and with electricity being expensive and unreliable, residents burn wood, coal, and waste materials for heating. The Cape Doctor weakens significantly in winter, and temperature inversions trap smoke close to the ground. Studies by the City of Cape Town have found PM2.5 levels in Khayelitsha reaching 100–200 μg/m³ on winter nights — far exceeding WHO guidelines. This creates a profound environmental justice issue: the wealthiest parts of Cape Town enjoy clean ocean air, while the poorest face some of the worst domestic smoke pollution in South Africa.
How does the Caltex oil refinery affect Cape Town's air?
The Caltex (Chevron) refinery at Paarden Eiland/Milnerton, one of South Africa's largest, processes approximately 100,000 barrels of crude oil daily. The refinery is the city's largest single industrial source of SO₂, NOx, VOCs, and hydrogen sulfide (H₂S — the characteristic 'rotten egg' smell that Cape Town residents sometimes detect on certain wind directions). Historically, the refinery's compliance record with South African air quality standards has been mixed. The area of Milnerton, Bloubergstrand, and parts of Paarden Eiland are most affected, especially when northwesterly winds bring refinery emissions toward the Atlantic Seaboard.
When is Cape Town's air quality best for visitors?
December through February is ideal — the height of the Cape Doctor season. Strong southeaster winds typically blow 30–50% of days in these months, giving Cape Town genuinely excellent air quality by global standards. Even Atlantic Seaboard suburbs that are naturally clean benefit from additional ventilation. The main risk in summer is occasional large veld fires in the Cape Fold mountains, which can create temporary smoky episodes. Autumn (March–April) is also generally excellent as winds remain moderate. The worst period is June–August when winter wood smoke from the Cape Flats can occasionally blanket even wealthier areas during calm nights.
Is Cape Town's air quality getting better or worse?
The picture is mixed. The City of Cape Town's own monitoring data shows gradual improvement in ambient PM2.5 and NO₂ levels over the past decade, largely due to improved vehicle emission standards and some industrial regulation. However, the fundamental issue of wood smoke from informal settlement heating has not been resolved — it remains the city's largest single air quality challenge. Electrification programs and the rollout of subsidized clean cooking fuels have made some progress in specific areas, but rapid urbanization continually adds new households in low-income areas that rely on solid fuels. Climate change is also extending the fire season, creating new veld fire smoke risks in formerly safe summer months.