This is why Joburg stinks: What’s behind the city’s rotten eggs smell?

The City of Johannesburg skyline has, over the past few days, seen a cloud of sulphur smog, which has led to residents smelling rotten eggs. Residents across several parts of the City of Johannesburg have spent the past few days asking the same question: why does the air smell like rotten eggs? From Sandton and Randburg to Roodepoort, Fourways, and Midrand, people have reported a strong sulphur-like odour hanging in the air.

The smell has not been limited to Johannesburg alone. Some residents in neighbouring areas beyond the city’s boundaries have also reported the same pungent scent. The unusual odour was first noticed earlier this year on January 16, 2026, and returned again on March 9, prompting concern and confusion among residents.

Many described a thick, unpleasant smell drifting across suburbs, with some initially unsure whether it was linked to industrial pollution, sewage, or another environmental issue. City officials say they began investigating the reports almost immediately. The City of Johannesburg’s Environment and Infrastructure Services Department (EISD) activated its air quality monitoring network after receiving complaints from residents.

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City Manager Dr Floyd Brink said the municipality moved quickly to assess the situation and identify the source of the odour. “Protecting the health and well-being of residents remains our priority. Our technical teams are actively monitoring air quality data and working with other spheres of government to determine the source of the odour and ensure residents are kept informed,” Brink said.

According to the city, weather conditions over the past few days have been typical of Johannesburg’s late summer climate, with warm temperatures, humid air, and intermittent rainfall. Such conditions can sometimes trap pollutants in the atmosphere and allow odours to linger. Monitoring data from the city’s air quality network confirmed elevated levels of hydrogen sulphide at two monitoring stations located in Buccleuch and Alexandra.

“Monitoring data confirmed elevated levels of hydrogen sulphide (H₂S) at the Buccleuch and Alexandra monitoring stations. On 9 March, fluctuating concentrations were recorded, with more pronounced spikes observed on 10 March at both stations,” the city said.

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