Petaling Jaya - The haze is back in the Klang Valley, Putrajaya, Pahang and Johor, and is expected to spread further inland over the next few days, said the Meteorological Department.
Its central forecasting office director Muhammad Helmi Abdullah said visibility in the Klang Valley had "reduced markedly" in a day, with the Kuala Lumpur International Airport in Sepang recording visibility of up to 2.5km yesterday afternoon.
"While this later improved, some areas in Petaling Jaya and Subang still had reduced visibility of up to 3km and 4km respectively," he told The Star.
As of 5pm yesterday, the Department of Environment's Air Pollutant Index recorded four areas with unhealthy air quality - Bukit Rambai in Malacca (119), Banting in Selangor (110), Muar in Johor (103) and Cheras in Kuala Lumpur (110).
Readings for Malacca city, Nilai and Port Klang hovered dangerously close to the unhealthy mark at 99, 96 and 94 respectively.
No readings were available for Putrajaya, which the DOE attributed to a technical error at the station.
The return of the haze comes just days after Indonesian Environment Minister Balthasar Kambuaya said his country hoped to ratify the 2002 Agreement on Transboundary Haze Pollution early next year after last week's meeting with four of his ASEAN counterparts.
The treaty aims to stop transboundary haze by requiring parties to prevent burning, monitor prevention efforts, exchange information and provide mutual help.
At the meeting, the ministers had commended Indonesia for its ability to put out the land and forest fires, resulting in a drastic drop in fires.
Its effort had included waterbombing raging fires on plantations in Riau and cloud seeding.
Last month, air quality levels turned hazardous in some parts of peninsular Malaysia as well as Singapore, resulting in the closure of schools and a spike in respiratory illnesses.
Muhammad Helmi said the haze was spreading at a slow rate with the light wind pattern, which was expected to remain steady throughout the week.
He said the haze had also reached parts of Pahang and Johor, and would move northwards to Perak and Penang.
"The main reason for the spread
has been the jump in the number of hotspots in Sumatra," he said, adding that drier weather conditions in the region would contribute to an increase in Indonesian forest fires.
According to the National Oceanic and Atmospheric Administration's latest reading on Sunday, Sumatra has 261 hotspots.
This is yet another sharp spike from 159 on Saturday, 43 on Friday and three on Thursday.
Malaysia also showed a jump in the number of hotspots to 19 on Sunday from five on Saturday.
The Singapore-based ASEAN Specialised Meteorological Centre's latest haze map showed moderate haze had spread from central Sumatra, where many hotspots are clustered together, towards peninsular Malaysia.
Singapore's The Straits Times Indonesian correspondent in Jakarta meanwhile reported that two Dumai-bound flights were forced to return to Pekanbaru yesterday morning due to poor visibility from the haze.
It said the airport in Dumai was closed for over a week when the haze last month was at its worst.
Muhammad Helmi said light to moderate rainfall was expected over the Klang Valley and Pahang, and slightly heavier rainfall over Johor after Thursday.
"There will be some reduction in the haze after the rain, but exactly how much haze it clears up remains to be seen," he said.