With global oceans having warmed significantly over the past 50 years, it may make a difference in predicting future El Nino Southern Oscillation (ENSO) events, the Australian Bureau of Meteorology (BoM) has said. 

On the other hand, Colombia Climate School International Research Institute (IRI) said an El Niño advisory from the CPC continues for February 2024, alongside a La Nina watch issued for June to August 2024.  

BoM said in its latest Climate Driver Update: “Based on the historical record from 1900, around 50 per cent of El Niño events have been followed by a neutral year, and 40–50 per cent have been followed by La Niña. However, global oceans have warmed significantly over the past 50 years.”  

Between April 2023 and January 2024, the oceans have been the warmest on record globally. These changes may have a say in predicting future ENSO events based on historical activity, BoM said.

Steady weakening

The Australian weather agency said a steady weakening trend in El Nino, which set in during June 2023, is evident in the oceanic indicators, though it persists. “Sea surface temperatures in the central tropical Pacific and temperatures in the Pacific sub-surface show a clear cooling trend, in line with typical event decay,” said BoM. 

Its view was supported by the IRI, which said: “As of mid-February 2024, moderate-strong El Nino conditions persist in the central-eastern equatorial Pacific, with important oceanic and atmospheric indicators aligning with an ongoing El Niño event that is gradually diminishing.” 

The Australian agency said international climate models suggest the central tropical Pacific Ocean will continue to cool in the coming months, with four of seven climate models indicating the central Pacific is likely to return to neutral ENSO levels in April (i.e., neither El Nino nor La Nina).


All models suggest neutral ENSO in May, but caution that predictions made in late southern summer and autumn tend to have lower accuracy than predictions made at other times of the year. This means that current forecasts of the ENSO state beyond May should be used with caution, it said.

IRI said almost all the models forecast a continuation of the El Nino event during the rest of the boreal winter and spring of 2024 (till June), which will rapidly weaken thereafter. 

“ENSO-neutral conditions become the most likely category in April-June, and May-July of 2024. For June-August 2024, no single category stands out as dominant, with ENSO-neutral and La Nina being almost equally likely. By July-September 2024, La Nina becomes the most probable category,” it said.

BoM said the Indian Ocean Dipole (IOD) had become neutral and will continue until at least April.