The Meteorological Service Singapore said that El Niño and a positive Indian Ocean Dipole could increase the risk of haze in Singapore [1].

These combined climate phenomena are significant because they typically suppress rainfall and increase temperatures. This creates drier conditions that make the region more susceptible to haze, which often results from regional forest and land fires.

According to the Meteorological Service Singapore, there is an eight in 10 probability of El Niño occurring this year [1]. The agency said El Niño is expected to develop during June and July and continue to strengthen toward September [1].

Adding to the risk is a predicted positive Indian Ocean Dipole, which is expected between July and August 2024 [1]. A positive Indian Ocean Dipole can further suppress moisture in the atmosphere, a condition that compounds the drying effects of El Niño.

The agency said the timeframe for increased haze risk is June to October 2024 [1]. Hotter temperatures and less rainfall are the primary drivers of this risk, as dry peatlands and forests become more flammable during these periods.

Singapore frequently faces transboundary haze when dry weather coincides with land clearing and burning in neighboring regions. The combination of these two specific climate drivers suggests a higher likelihood of severe air quality degradation during the identified window [1].

“There is an eight in 10 probability of El Niño occurring this year.”

The convergence of El Niño and a positive Indian Ocean Dipole creates a 'double hit' of dryness for Southeast Asia. Because both patterns independently reduce precipitation and raise temperatures, their simultaneous occurrence increases the likelihood of uncontrollable wildfires in the region, which inevitably leads to transboundary haze affecting Singapore's air quality.