Likewise in 1997 and 2015, the year of 2019 so far is relatively dry with the observed influence of weak El-Nino and positive Indian Ocean Dipole (IOD). The combination of these two phenomena results in low rainfall rate and even move the onset of wet season further.
A number of studies have discussed the link between active El-Nino, positive IOD, and fire intensity in Indonesia. Intensive and prolonged fire season indeed occurs during El-Nino years, this includes the events of 1997 and 2015. The fire season is at least twice as intensive when the IOD is positive than when it is negative. In 1997, El Nino phase was stronger compared to 2015 where the temperature anomalies were twice higher. The meteorological agencies of Indonesia and Australia have reported that El-Nino influence has weakened in September 2019 while the positive IOD is likely to persist until December.
In short, El-Nino phase and positive IOD result in less precipitation that should have naturally diminished forest and land fire.