The National Environment Agency (NEA) has pointed to local pollution as the cause of Thursday morning's haze in a surprise move that absolves Indonesia from blame.
Indonesia has faced years of ridicule for its forest burning agricultural tactics, which many experts have blamed for serious trans boundary air pollution in recent years.
"Based on the latest satellite images, there were no significant hotspots or smoke haze detected in the nearby region," said a spokesman for the National Environment Agency (NEA).
"The haziness was due to the accumulation of particulate matter under light wind conditions," the spokesman added.
The 24 hour Pollutant Standards Index (PSI) reached a maximum of 95 in Singapore at 8AM yesterday. Any reading above 100 indicates unhealthy air quality, while a reading between 51 and 100 is moderate.
"Another significant source of our poor air is exhaust from traffic," said environmental volunteer group PM.Haze executive director Zhang Wen.
Usually, domestic pollution is blown away by the wind, she said. "But as it was not windy yesterday, the pollutants could not disperse, making it look hazy."