The 24-hour PSI is computed based on six air pollutants – PM2.5, PM10, ozone, sulphur dioxide, nitrogen dioxide and carbon monoxide.
With northeasterly winds carrying smoke to Singapore, 1-hour PM2.5 levels in certain regions could increase, depending on the wind conditions, NEA said.
NEA advised the public to refer to the 1-hour PM2.5 levels when carrying out outdoor activities in the immediate hour.
Clinics in Singapore have reported a rise in haze-related cases over the past three months, with patients presenting not only respiratory symptoms but also issues like itchy eyes and skin flare-ups.