SINGAPORE - After recent months of clear skies, it looks like the haze is back in Singapore.
As of 8pm on Wednesday (March 30), the 24-hour PSI reading was 66 to 84, which is in the moderate range.
A 24-hour PSI reading of 0 to 50 means air quality is in the good range, while a reading of 51 to 100 means it is in the moderate range.
The 24-hour PSI has hovered nearer 40 to 60 in recent months, and this is the first noticeable spike this year.
The three-hour PSI, which is not tied to health advisories, was 89 at 8pm, following a short spike the night before when it hit 87 at 8pm.
Since Tuesday afternoon, Singapore skies turned grey and a burning smell lingered in the air.
According to a Xinhua report on Tuesday, an observation by Nasa's Terra and Aqua satellite on Tuesday detected that the number of forest hot spots in Indonesia had risen to 40 from 13 on March 18.
Thirty-seven of the hot spots are in Sumatra, and three others in Sulawesi, Maluku and Papua, the report said.
However, in an update on the website of Singapore's National Environment Agency (NEA) on Tuesday, hot spot activities were said to be subdued in the southern Asean region due to wet weather conditions, with only isolated hot spots detected in Brunei.
Meanwhile, scattered hot spots have been detected over Vietnam, Laos and Cambodia.
Singapore suffered one of its worst bouts of haze last year with the extended El Nino season.
PSI readings reached hazardous levels in September 2015, leading to the closure of primary and secondary schools.