PETALING JAYA, Sept 14 — The air quality in the country yesterday was the worst this year with only one area recording healthy air pollutant index (API) reading, while the rest were either moderate or unhealthy.

The worst hit unhealthy area was Bukit Rambai in Malacca, which recorded a reading of 171 at 4pm, up from 148 at 6am. It improved at 6pm (168).

The only area with a good API reading throughout the day was Tanah Merah in Kelantan. Kuala Terengganu improved from moderate to good at 5pm.

An API reading of between 0 and 50 is categorised as good; 51 to 100, moderate; 101 to 200, unhealthy; 201 to 300, very unhealthy, and 300 and above, hazardous.

Besides Bukit Rambai, the other areas with unhealthy readings (as of 4pm) were Muar (148), Pasir Gudang (106), Bandaraya Melaka (166), Nilai (160), Port Dickson (160), Seremban (154), Kuching (120), Samarahan (126), Sri Aman (108), Banting (166), Kuala Selangor (109), Port Klang (153), Petaling Jaya (146), Shah Alam (151), Batu Muda (132), Cheras (128) and Putrajaya (155).

The Asean Specialised Meteorological Centre detected 53 hotspots in Sumatra and 97 in Kalimantan on Saturday.

Only two hotspots were recorded in the country the same day, each in Terengganu and Sarawak.

National weather centre spokesman Dr Mohd Hisham Mohd Anip told Malay Mail the situation was expected to improve today.

“The haze is really bad because the wind is slow ... almost calm. By tomorrow (today), we expect stronger wind and the direction will change from south to west,” he said.

The transboundary haze was expected to ease because the south-west monsoon would end in mid-September, to be replaced by the transitional monsoon until early November.

“During this monsoon, the country will be more humid especially on the west coast of the peninsula and West of Sabah,” the Meteorological Department said in the statement.

In terms of visibility, the lowest reading yesterday was in Petaling Jaya and Sepang at 400m and 500m respectively at 10am, according to the Meteorological Department’s website.

Visibility in Petaling Jaya was below 1km, while Sepang had improved by noon but deteriorated in the evening.