It might be time to pull out those N95 masks again, as the first signs of haze appeared in Singapore this morning. The 24-hour Pollutant Standards Index (PSI) was at the high end of the moderate range in the early hours on Friday (April 21).
As of 11am, it was highest in the south of the island at 93. A PSI reading of 100 indicates unhealthy air quality, while a reading of 51 to 100 means moderate air quality.
The PSI has been inching upwards since Thursday but the National Environment Agency (NEA) said in a late morning update that there were no significant hotspots or smoke haze detected in the nearby region.
"The haziness was due to the accumulation of particulate matter under light wind conditions," it said.
In the east, it reached 86, and in the north, 84. It was 61 in the west and 80 in the central region.
The one-hour PM2.5 reading was between two and three, which is normal (Band I).
Band I, ranging from 0 to 55, is normal while Band II (56 to 150) is elevated.
A Sumatra squall in the morning helped to clear the hazy conditions, NEA said. The rest of the day is expected to be cloudy with light rain clearing in the afternoon.
The PM2.5 concentration readings are an indicative measure of the current air quality and can be used to plan one's immediate activities.
Most people can continue their normal activities while the 24-hour PSI is moderate, according to NEA website.
Here are some ways you can combat the haze at home:
Article by Chew Hui Min, originally appeared in The Straits Times.