Climate outlook for October to December

Issued 27 September 2018

Climate outlook overview

The October to December climate outlook, issued 27 September 2018, indicates parts of eastern and southern Australia are likely to be drier than average.
October shows a strong likelihood of drier conditions across most of the eastern two-thirds of the country, and southwest WA. However, there are exceptions along parts of the east coast of Australia to the east of the Great Dividing Range, where there is no strong indication of either a wetter or drier month.
October to December days are very likely to be warmer than average for most of Australia. Nights are also likely to be warmer than average for most of Australia.
A drier and warmer than average end to the year would mean a low chance of recovery for drought-affected areas of eastern Australia.
The El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are currently neutral. However, current observations and model outlooks indicate El Niño and a positive IOD could develop in spring. See the Climate Influences section for more information.

October to December is likely to be drier than average for parts of eastern and southern Australia. Specifically, scattered parts of Queensland, eastern SA, Tasmania, Victoria, southern and western NSW, along with southwest WA and parts of the NT are likely to have a drier than average October to December.
October is likely to be drier than average for large areas of Australia, but there are roughly equal chances of a wetter or drier three months over most of WA, western SA and parts of the east coast to the east of the Great Dividing Range.
Much of eastern and southern mainland Australia have been very dry and warm since the start of the year. The October to December outlook indicates current drought areas are unlikely to see significant respite in the coming three months.
Historical outlook accuracy for October to December is moderate to high over most of the country, except for WA's Interior District where accuracy is low to very low. See map for more detail.

The above average daytime temperatures observed across Australia so far in 2018 are likely to continue for the remainder of the year.
October to December days are very likely to be warmer than average for most of Australia. Chances of a warmer three months are greater than 80% over most of the country.
Nights are also likely to be warmer than average across Australia, except for the northeastern NT and the northern to central coast of Queensland, where the chances of warmer or cooler nights are roughly equal.
Historical accuracy for October to December maximum temperatures is high to very high across most of Australia, and low to moderate in Tasmania. Minimum temperature accuracy is moderate for most of the southern half of Australia, and the Top End of the NT and far north Queensland. Elsewhere, accuracy is low to very low.

The El Niño–Southern Oscillation is currently neutral, but El Niño may develop by late spring. El Niño typically results in below-average spring rainfall for northern and eastern Australia, and warmer days for the southern two-thirds of the country. By summer, the reduced rainfall influence from El Niño contracts to the tropical north.
The Indian Ocean Dipole (IOD) is also neutral, although recent values and model outlooks suggest a positive event may be emerging. A positive IOD during spring typically reduces rainfall across much of the eastern two-thirds of Australia and can exacerbate any El Niño-driven rainfall deficiencies. However, IOD events usually decay by the start of summer.
Sea surface temperatures to Australia's northwest are average to cooler than average; a pattern which can suppress rainfall over southern and central Australia.
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.

Product code: IDCKOATCO2