Environment department director-general Wan Abdul Latiff Wan Jaafar said the API reading in Putrajaya reached 139 as at 3pm, while the reading in Nilai, Negeri Sembilan, crept up to 162 from 156 recorded at 9am.

In Selangor, the API reading in Banting increased from 151 to 154, but it dropped minimally in Johan Setia (Klang) from 155 to 154, within the same period.

In Alor Gajah, Melaka, the API reading reached 110.

The data, from the environment department’s air pollutant index management system, represents an average of readings taken over 24 hours, updated hourly. An index figure of below 50 indicates good air quality, 51-100 moderate, 101-200 unhealthy, 201-300 very unhealthy, and above 300 hazardous.

Wan Abdul Latiff said 57 areas recorded moderate air quality and six areas registered good air quality.

He said the air quality deterioration was influenced by the movement of smoke and haze entering the west coast region of the country over the past 24 hours.

“No large-scale fires in the country have been detected,” he said.

According to the Asean Specialised Meteorological Centre (ASMC) in Singapore, satellite images from yesterday showed 65 hotspots in Sumatra, 30 in Kalimantan and four in Malaysia – two each in Pahang and Selangor.

Wan Abdul Latiff said ASMC’s regional haze map today showed wind blowing southwest, with no major haze plumes observed.

“Dry conditions were reported across southern Peninsular Malaysia, Sumatra, Java, the Lesser Sunda Islands and southern Kalimantan.

“Isolated hotspots were detected in Sumatra, with several more in Peninsular Malaysia, Kalimantan, Vietnam and Thailand,” he said.