Climate outlook for August to October

Issued 28 July 2016

Climate outlook overview

August to October rainfall outlook shows above average rainfall is likely for eastern and northern Australia.
For maximum temperatures, warmer days are likely in the north and Tasmania, while cooler days are likely in the east.
For minimum temperatures, warmer nights are likely in northern and central Australia, and the far southeast. Cooler nights are more likely in small parts of the east.
Climate influences include a strong negative Indian Ocean Dipole, a continued cooling of tropical Pacific Ocean waters, and very warm sea surface temperatures surrounding northern and eastern Australia (see the Climate Influences section).

August to October rainfall is likely to be above average across eastern and northern Australia. The western half of Australia has roughly equal chances of a wetter or drier three months.
August is likely to be wetter for eastern and northern Australia.
The current outlook reflects a strong negative Indian Ocean Dipole, a continued cooling of tropical Pacific Ocean waters, and very warm sea surface temperatures surrounding northern and eastern Australia.
Historical outlook accuracy for August to October is moderate over most of Australia, but low in parts of central Queensland and interior WA. See map for more detail.

For August to October, warmer than average days are more likely for Tasmania and the tropical north extending down into northwestern WA. Cooler days are more likely in the east, and southern parts of WA.
Night-time temperatures are more likely to be warmer across northern and central Australia, and the far southeast. Parts of southeast Queensland and northeast NSW are more likely to have cooler than average nights for August to October.
The current outlook reflects a strong negative Indian Ocean Dipole, a continued cooling of tropical Pacific Ocean waters, and very warm sea surface temperatures surrounding northern and eastern Australia.
Historical maximum temperature accuracy for August to October is moderate over the southern half of mainland Australia, Queensland and the Top End of the NT. Elsewhere, accuracy is low. Minimum temperature accuracy is moderate over northern Australia, parts of SA, northern NSW, and Tasmania, but low elsewhere.

The current negative Indian Ocean Dipole (IOD) pattern is expected to persist through to the end of spring. Historically this has meant above average rainfall and cooler days for southern parts of Australia, with warmer days and nights in the north. The climate outlook is generally consistent with these negative IOD impacts.
The tropical Pacific is neutral, with sea surface temperatures showing a cooling trend since late last year. By August, the Bureau's model suggests the Pacific may have reached borderline La Niña conditions. In periods when La Niña is developing or near thresholds, some areas typically experience La Niña-like impacts, including above average rainfall outlook across eastern and northern Australia.
Tropical sea surface temperatures around Australia’s north are warmer than average. Likewise, waters along the entire eastern Australian coast, and surrounding Tasmania, are also warmer than normal. With favourable weather patterns, these can result in increased localised rainfall. Warmer waters in the eastern Indian Ocean may provide extra moisture for rain-bearing systems as they cross Australia.
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.