Though slight now, the haze could worsen in the coming months, and peak in September, deep into the dry season.
Yesterday, 32 hot spots were detected in Sumatra, and 50 in Borneo. Meteorologists are watching as an early-stage El Nino develops over the Pacific Ocean.
In fact, all it would take now for haze to blow by is for the wind to change, said experts. It has already blanketed parts of neighbouring Malaysia.
The pollution standards index (PSI) peaked at an unhealthy 136 in areas such as Port Klang, Shah Alam and Cheras last week, as visibility and air quality deteriorated rapidly.
In Singapore the PSI is in the good range for now. But similar hot and dry weather in 1997 and 2006 fuelled fires in Indonesia, and south-westerly winds sent the smoke onwards.
The haze lasted three months in 1997, with the PSI reaching an all time high of 226 in September. People stayed indoors, health-care costs soared and tourism was disrupted.
According to a World Wide Fund for Nature (WWF) report published in 1998, Singapore, Indonesia and Malaysia suffered losses of more than $2.1 billion in the toll to their economies.
A bad haze year would also have a worrying impact on the prize event in the tourism calendar, the F1 Grand Prix race held in September, the minister said yesterday.
Singapore will continue to work with Indonesia by providing it with the latest up-to-date information of where hot spots are, so that it can do its part, said Dr Yaacob.
Singapore has committed $1 million to help the provincial government implement various programmes designed to prevent or mitigate the incidence of fires.