Haze may ease by month-end as monsoon rains arrive - Academic

ARAU: The haze affecting Malaysia is expected to gradually improve by the end of this month as the country enters the monsoon transition phase, which could bring more rain and changes in wind direction and speed.

Universiti Malaysia Perlis (Unimap) Faculty of Civil Engineering and Technology associate professor Dr Norazian Mohamed Noor said these factors could help reduce atmospheric pollutant concentrations and limit the cross-border movement of smoke from Indonesia.

She said the Malaysian Meteorological Department's (MetMalaysia) long-range weather outlook for October to March 2027 indicated that most parts of the country were expected to receive rainfall close to their climatological averages from this month until December.

Selangor, for example, was forecast to receive between 220mm and 330mm of rain this month, and between 250mm and 380mm in November.

Kuala Lumpur, meanwhile, was expected to receive between 240mm and 360mm of rain in October, rising to between 300mm and 450mm in November.

"These conditions offer a positive indication that increased rainfall could help improve air quality in Malaysia. However, the recovery may not occur simultaneously across all areas.

"Haze conditions are influenced not only by rainfall in Malaysia but also by fire activity, rainfall distribution in pollution-source areas and wind direction.

"Rainfall in our country alone is insufficient to ensure an end to transboundary haze if fires remain active at their source in Indonesia," she said recently.

Norazian said an analysis by Indonesia's Meteorology, Climatology and Geophysics Agency (BMKG), dated Oct 13, indicated that parts of southern Sumatra, West Kalimantan, Central Kalimantan and South Kalimantan were still expected to receive low rainfall of less than 50mm over certain 10-day periods this month.

She said the conditions could increase the risk of forest and peatland fires, particularly in areas experiencing prolonged dry spells.

"However, the BMKG forecast also indicated increased rainfall in several parts of Sumatra and Kalimantan in November and December, with some areas potentially receiving more than 300mm of rain a month.

"Should the rainfall be continuous and cover fire-affected areas, it could help reduce fire activity and smoke emissions," she said.