Climate outlook for October to December

Issued 14 September 2017

Climate outlook overview

The October to December outlook, issued 14 September 2017, shows an equal chance of wetter or drier conditions across Australia.
This means there is no strong driver pushing our climate towards widespread significantly wetter or drier conditions.
October is likely to be drier for the Pilbara and surrounds, but wetter than average for eastern Tasmania.
Daytime temperatures are likely to be warmer than average for the northwestern half of Australia and the southeast for October to December.
October to December nights are likely to be warmer than average over the northern half of Australia, and most of the eastern States. Chances are highest—greater than 80%—in the far north and southeast Australia.
Climate influences from the Indian and Pacific oceans are likely to be competing, with a weak drying influence from the Indian Ocean potentially cancelling out a slightly wet influence from the Pacific Ocean. See the Climate Influences section for more information.

Equal chance of a wetter or drier three months for Australia.
October is likely to be drier for the Pilbara and surrounds, but wetter than average for eastern Tasmania.
Climate influences from the Indian and Pacific oceans are likely to be competing, with a slightly drying influence in the Indian Ocean potentially cancelling out a slightly wetter influence from the Pacific Ocean.
Historical outlook accuracy for October to December is moderate for most of Australia, but low in northern and southern parts of WA, and southern SA. See map for more detail.

Daytime temperatures are likely to be warmer than average for the northwestern half of Australia and the southeast for October to December.
October to December nights are likely to be warmer than average for the northern half of Australia, and most of the eastern States. Chances are highest—greater than 80%—in the far north and southeast Australia.
For October, cooler nights are likely for southern WA, and SA extending into southwestern Queensland. Warmer October nights are more likely in southeast and northern Australia.
Historical accuracy for maximum temperatures is moderate to high over most of Australia, except for western WA, where accuracy is low. Minimum temperature accuracy is moderate to high for large parts of Australia, but low for parts of the NSW and Queensland coast; the Kimberley in WA extending east into the NT; and the western Pilbara in WA.

The Indian Ocean Dipole (IOD) remains neutral, but has been weakly positive (though below the positive IOD threshold) for the past six weeks.
The El Niño–Southern Oscillation (ENSO) is also neutral, despite eastern tropical Pacific Ocean temperatures cooling over the past two months. Pacific sea surface temperatures may approach La Niña thresholds during spring, before easing back towards normal in summer.
These influences from the Indian and Pacific oceans are likely to be competing, with a weak drying influence in the Indian Ocean potentially cancelling out a slightly wet influence from the Pacific Ocean.
In addition to the natural drivers such as the El Niño–Southern Oscillation and the IOD, Australian climate patterns are being influenced by the long-term increasing trend in global air and ocean temperatures.
Bureau climatologists continually monitor the climate for any significant developments, with information on El Niño/La Niña and IOD events available fortnightly via the ENSO Wrap-Up. For a summary of Pacific and Indian Ocean outlooks, please see the Climate Model Summary.