Air pollution in Dumai in Riau province hit a record high yesterday, with visibility at the city's airport the worst in years, officials said.
The Air Pollutant Index (API) reached 500 in the morning, before it went down around noon as strong winds blew the thick haze southwards, away from neighbouring countries.
Dumai, about 270km north-west of Singapore, was at the centre of June's extreme haze as farmers slashed and burned to clear land, causing air pollution to hit record highs in nearby Singapore and Malaysia.
Already, the API in Dumai has surpassed the peak of 460 recorded in June last year. Then, Indonesia was forced to resort to cloud- seeding to induce rain.
It also dumped water from airplanes to douse plantation and forest fires in the Indonesian province second-closest to Singapore.
Visibility was as low as 25m at Dumai's Pinang Kampai airport between 6.30am and 8am local time yesterday. It went back up to above 1,000m several hours later, thanks to strong winds.
Mr Toto Sumartomo, the operations manager of Pelita Air, which plies the Jakarta-Dumai route, told The Straits Times: "The haze situation has matched what happened in June. But the winds are stronger this time round."
The head of Riau's environmental health office, Mr Dewani (who goes by one name), said: "PSI at 500 means it is very hazardous." It was recorded at 7am local time by Chevron Pacific Indonesia, which operates oil fields in Riau. "Anything above 300 is deemed very hazardous."
An unusual dry spell in Riau since late December has seen farmers taking the opportunity to start fires to clear land, creating haze over the city of Dumai and elsewhere in Riau province.
Open burning is against Indonesian law but the law is widely flouted.
In a strong signal to errant businesses, Singapore's Environment and Water Resources Ministry earlier this week proposed a new law on transboundary haze.
Firms with haze-producing fires on their land that affect Singapore can be punished with fines of up to $450,000 under the proposed law.
The proposed legislation is a direct response to Singapore's worst-ever bout of haze in June last year, which was caused by fires lit to clear land in Sumatra.
Yesterday, Dumai residents appealed to the local authorities to take action.
Shop owner Adek Sanjaya, 47, who has three school-going children, said: "As parents, we want the education department to temporarily close schools. We also want the mayor to take any necessary measures to prevent this haze disaster from recurring every year."
In Pekanbaru, the capital of Riau, the haze cleared yesterday, with no flight delays reported.
On Wednesday morning, 16 flights in and out of the airport were delayed for several hours due to thick haze. Haze is usually thicker in the morning hours because of the morning fog.