Jakarta tightens air-quality monitoring as Mount Anak Krakatau ash spreads

Jakarta is intensifying air-quality monitoring after volcanic ash from Mount Anak Krakatau spread across parts of the city, with officials urging residents to limit time outdoors and protect themselves from renewed exposure.

The Jakarta Environmental Agency is coordinating with the BMKG, PVMBG, BPBD and the Health Agency. Agency head Dudi Gardesi said monitoring would guide public warnings and protective measures. “Any change in conditions must be immediately followed by updated information so that residents know what steps to take,” he said.

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Any change in conditions must be immediately followed by updated information so that residents know what steps to take. The protection of sanitation workers in the field must also be ensured.

BMKG information recorded at 5 a.m. on September 6, 2026, indicated that volcanic ash had reached parts of Jakarta. Residents in affected areas or places with poorer air quality were advised to postpone outdoor exercise and avoid non-essential outdoor activities. Anyone who must go outside should wear a tightly fitting N95 mask or equivalent.

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If you must go out in an ash-affected area, wear an N95 mask or an equivalent that fits tightly over your nose and mouth.

During ashfall, authorities advised people to stay indoors and keep doors and windows closed. Children, older people, and those with asthma, lung disease or heart disease require particular attention. Schools, event organizers and employers were told to adjust outdoor activities according to local conditions.

Officials also issued instructions for cleaning ash deposits. Residents should use a damp cloth or mop rather than dry sweeping or blowing the ash, which can send it back into the air. Masks and eye protection should be worn, while food, drinking water and water-storage containers should be covered. People with persistent breathing problems or eye irritation should seek medical care, and anyone facing severe shortness of breath or another emergency should call Jakarta Siaga 112, a free 24-hour service.

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Regarding sanitation workers, I have instructed my staff to prioritize the availability of masks and eye protection, as well as safe work arrangements.