Haze Update: PSI drops slightly again to 139 at 6pm

Haze conditions in Singapore eased slightly but remained unhealthy as the Pollutant Standards Index (PSI) dropped to 139 at 6pm on Friday, down from 143 at 5pm.

Readings between 101 and 200 are considered unhealthy. An all-time high of 401 was recorded at noon, well into the "hazardous" range of 300 and higher. The PSI has been steadily decreasing since then.

The 24-hour average PSI at 6pm was 161-200, also down slightly from 166-216 an hour earlier.