The Bureau of Meteorology (BoM) has issued a significant reality check about Australia's current El Niño, warning that while the event is on track to potentially become the strongest ever recorded, that does not automatically translate into an exceptionally hot and dry summer for the country.
In an advisory released Tuesday, the BoM said climate models indicate the current El Niño could produce the highest central tropical Pacific sea surface temperature anomaly since reliable records began in 1950 — with forecasts suggesting temperatures could climb more than 3°C above average. For context, the record-holder, the 1982–83 El Niño, peaked at around 2.6°C above average in January 1983.
Why a record El Niño doesn't mean a record-breaking Australian summer
Despite the striking forecast, the BoM has been clear: the raw strength of an El Niño event is not a direct indicator of how severely it will affect Australians on the ground.
"Every El Niño is different," the bureau stated. "A strong event can produce only modest effects in some regions, while a weaker event can have significant impacts."
Australia's climate is shaped by a complex interplay of drivers well beyond El Niño alone. The Indian Ocean Dipole (IOD), surrounding sea surface temperatures, seasonal patterns, and the long-term influence of climate change all play a role in determining actual rainfall and temperature outcomes across the continent.
The current IOD is neutral, though all major climate models suggest it could shift to a positive phase later in spring. A positive IOD typically raises the likelihood of drier conditions across southern and eastern Australia — compounding potential El Niño effects in those regions.
Rainfall and temperature outlook: a mixed picture
The BoM's latest long-range forecast, issued on 10 September, paints a varied picture depending on where in Australia you live.
Most of the country is expected to experience above-average temperatures in the months ahead. However, rainfall projections diverge significantly by region:
- Below-average rainfall is likely across parts of south-eastern Australia between October and December, including southern New South Wales, Victoria, and Tasmania.
- Above-average rainfall is forecast for most of Western Australia and parts of central and northern Australia.
The BoM also noted that El Niño's influence on Australian rainfall typically begins to diminish around early summer, though the current event is expected to persist through spring and into the summer months.
With hotter and drier conditions possible across parts of the south-east, bushfire risk is a concern — though the bureau stressed that local conditions and short-term weather systems will also be critical factors. Climate change, it added, is independently increasing the likelihood of more frequent and intense heat events. With a potentially dangerous summer on the horizon, health warnings ahead of the Australian summer are already gaining attention.
How we got here: from La Niña to El Niño in a matter of months
The rapid shift in Australia's climate pattern this year has been striking. The year began under an active La Niña, which delivered a very wet northern wet season and above-average rainfall across large parts of the country. Conditions then transitioned sharply toward El Niño during autumn, with the event officially declared by June.
The previous El Niño, which developed in spring 2023 and ran into early 2024, was classified as a moderate-to-strong event. The current event is already shaping up to surpass it in terms of sea surface temperature anomalies.
Despite El Niño's well-known association with dry and hot conditions in Australia, 2025 has so far been wetter than average across large parts of the country — a reminder that climate drivers interact in ways that rarely produce textbook outcomes.
The BoM's message, in short: prepare for variability, not certainty — and don't assume the record books tell the whole story.
