KUALA LUMPUR, Sept 30 — Two areas in Selangor and one in Negeri Sembilan have hit unhealthy levels as of 9am this morning, according to the hourly readings released on the Air Pollutant Index Management System (APIMS) website.

As of 9am today, the air pollutant index (API) reading for Cheras was the highest at 152, followed by Nilai (135) and Shah Alam (114).

The Asean Specialised Meteorological Centre (ASMC) put out an alert yesterday warning that the dry weather conditions that have prevailed over the past week had caused a large number of hotspots to arise yesterday evening.

It said that based on surveillance from the National Oceanic and Atmospheric Administration NOAA-20 satellite, 241 and 145 hotspots were detected in Sumatra on September 27 and 28.

"Moderate to dense smoke haze was observed to emanate from clusters of hotspots detected in central and southern parts of Sumatra.

"While some isolated showers are forecast for Sumatra in the coming days, dry weather is expected to persist in parts of central and southern Sumatra, with the prevailing winds likely to continue blowing from the southeast or southwest.

"Under these conditions, the hotspot and smoke haze situation there could worsen, with an increased risk of transboundary smoke haze occurrence,” the alert read.

This was corroborated by Datuk Wan Abdul Latiff Wan Jaffar, the director-general of Malaysia’s Department of Environment, who said that forest fires in Indonesia had caused transboundary haze to affect East Malaysia.

"Satellite imagery from the National Oceanic and Atmospheric Administration detected 52 hotspots in Sumatra, 264 hotspots in Kalimantan, and no hotspots detected within (Malaysia),” he was quoted sa saying by Free Malaysia Today.

Air pollution levels were high in several areas in Selangor, Negeri Sembilan and Penang yesterday following the humid weather.

No areas of Sabah or Sarawak are showing unhealthy levels as of the time of writing.