The number of hot spots in Indonesia's Riau province has declined, although poor visibility has been reported in some areas, particularly in the east, because of forest fires.
Antara news agency said thick haze has blanketed parts of the province and forced schools to send students home.
The number of hot spots came down from 54 last Friday to 23 yesterday, said Mr Sukisno, head of the Meteorology, Climatology and Geophysics agency at Pekanbaru in Riau.
But the number has been fluctuating, with 44 recorded last Saturday and 47 on Sunday.
On Monday, it went down to 32.
The Indonesian military has deployed an aircraft to the province and Mr Sukisno, who goes by one name, said cloud-seeding operations to induce rain should begin today.
Some areas in the eastern part of Riau have not seen rain since mid-January. During dry season like now, we do experience rainfall but within the light to moderate range.
MR SUKISNO, head of the Meteorology, Climatology and Geophysics agency at Pekanbaru in Riau.
Visibility in Riau's Rupat island in the Malacca Strait was as low as 100m, Antara reported, citing the local authority. The island off the city of Dumai has not received any rainfall for about a month.
"Some areas in the eastern part of Riau have not seen rain since mid-January. During the dry season like now, we do experience rainfall but within the light to moderate range," Mr Sukisno told The Straits Times.
"Eastern parts of Riau, a coastal area, generally see lower rainfall than the province's inland areas in the west."
There are currently no hot spots in the western part of Riau.
"Wind direction trends during the February-March period are easterly and north-easterly (blowing from east towards west and from north-east towards south-west), or away from Singapore," Mr Sukisno added.
Riau has two dry seasons a year - February-March and June-August - and the wind direction in the latter season would be towards the north-east, or in the direction of Singapore and the Malaysian peninsula, Mr Sukisno said.
Most other parts of Indonesia experience the dry season only once a year.
It is between April and September on the most populous island of Java, and the rest of the year is considered the rainy season.
Forest fires were among the issues that cropped up during the recent presidential debate on Feb 17, with the incumbent, Mr Joko Widodo, touting his achievement in curbing the fires.
Mr Joko is facing former army general Prabowo Subianto, 67, in the April 17 polls.
Mr Joko, 57, popularly known as Jokowi, is seeking a second and final five-year term in office.
Mr Joko's campaign managers say the current administration has managed to reduce forest and plantation fires through stricter law enforcement and prevention measures.
"During Jokowi's tenure, forest fires have been handled quickly and the problem did not persist," senior politician Lukman Edy, representing Mr Joko's campaign team, told the Jakarta-based Elshinta radio a day after the Feb 17 debate, the second of five scheduled to take place between the two main candidates before the poll.
Mr Lukman said that there had been only one major fire - in 2015 - under Mr Joko. Previously, such incidents were annual occurrences.
"We almost never have forest fires any more. Lately, there were hot spots emerging, but firefighting teams promptly handled them," Mr Lukman said.
"Forest fires are unavoidable, but the government now is there to deal with them, so the problem does not drag on."
There has hardly been any response from the Prabowo camp to the President's claims.