The El Niño–Southern Oscillation (ENSO) remains neutral – neither El Niño nor La Niña. The ENSO Outlook is INACTIVE, meaning there is little sign of El Niño or La Niña developing in the coming months.

Oceanic and atmospheric indicators reflect this neutral state. Sea surface temperatures remain cooler than average, but within the neutral range. However, waters beneath the surface have warmed, and will likely extend to the surface in the coming weeks to months. In the atmosphere, trade winds and cloudiness patterns are near normal, consistent with a neutral state. Although the 30-day Southern Oscillation Index (SOI) has bounced back into the La Niña range, this is a result of transient tropical systems, including tropical cyclones Marcus and Nora, and does not reflect the broader climate state.

Most international models surveyed by the Bureau indicate the tropical Pacific Ocean is likely to remain ENSO-neutral through the southern hemisphere autumn and into winter. A neutral ENSO pattern does not necessarily indicate average rainfall and temperature for Australia. Rather, it indicates a reduced chance of widespread very wet or very dry weather, and that other climate drivers may have greater influence over the coming months.

The Indian Ocean Dipole (IOD) is currently neutral. IOD events are unable to form between December and April. Four out of six international models suggest a neutral IOD for autumn and early winter, while two show a shift towards a negative IOD during winter. A negative IOD during winter tends to enhance rainfall in southern Australia. However, model accuracy during autumn is lower than at other times of year, so these outlooks should be used with caution.