During Southwest Monsoon season in 1997, Southeast Asia experienced one of the worst haze episodes in history. That year, Indonesia experienced drought conditions brought about by a record-breaking El Nino in 1997-1998, which provided conducive conditions for outbreak of fires. The traditional land clearing activities by farmers then resulted in widespread and prolonged burning of forested land in Sumatra and Kalimantan. Large areas of smoke haze were blown towards Brunei, Malaysia, Thailand and Singapore between August and October 1997 by the prevailing southeasterly/southwesterly winds. Air quality in Singapore reached very unhealthy levels and visibility dropped to below 300 m. The hazy conditions improved in November with the onset of the Northeast Monsoon season.
Widespread haze (indicated as yellow shades) shrouded Singapore and the neighbouring countries. On 18th September, our local 3-hour PSI level hit a peak of 226.
Significantly lower than average rainfall in 1997 across the region including Singapore due to the record-breaking 1997-1998 El Niño phenomenon.