Haze worsens as air quality hits "unhealthy" levels

SINGAPORE - The haze situation seems to be rapidly worsening after a momentary respite during the weekend.

The three-hour Pollutant Standards Index (PSI) rose to 105 as of 3pm today - putting it within the "unhealthy" range of 101 to 200 PSI value.

This is a sharp jump from the three-hour PSI reading of 56 this morning at 7am. A PSI reading of 51 to 100 indicates air quality here is at a "moderate" level.

The index hit the previous high of 88 last Friday before abating over the weekend to a Saturday high of 79 at 6pm.

The National Environment Agency (NEA) warned that hazy conditions are expected to persist for the next few days, as south-westerly winds carry smoke in this direction from forest fires in Sumatra.

In a latest statement updated today, NEA said that Southwest Monsoon conditions have begun in the region since the beginning of the week, with low level winds blowing predominantly from the southeast or southwest.

The Southwest Monsoon season typically last from June to September and is the traditional dry season for the southern ASEAN region.

In the coming months, occasional extended periods of drier weather can be expected in the region. During the season, increased hot-spot activities may be expected in Sumatra and Borneo, NEA said.

Hence, trans-boundary smoke haze could affect the region during periods of persistent dry weather conditions.

In recent days, weather conditions in the region have become drier and an increase in hot-spot activities has been observed mainly over central Sumatra.

On June 16, 138 hot-spots were detected over Sumatra.

NEA explained that the haze here is caused by smoke from these fires, brought over by prevailing winds blowing from the southwest or west.

According to the 12pm update of the 24-hour PSI index, the highest PSI readings were recorded in the South and West at 75 and 74 respectively.

The North has the lowest 24-hour PSI reading of 64, followed by the East (67) and Central (68).

NEA advised people with heart or lung diseases, children and older adults to avoid all physical activity outdoors.

Everyone else should avoid prolonged or heavy exertion.

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