Climate outlook for spring (September to November)

Issued 31 August 2017

Climate outlook overview

The spring outlook, issued 31 August 2017, shows rainfall is likely to be below average in southwest Australia, above average in parts of southeast Queensland, and has a roughly equal chance of being above or below average elsewhere.
Daytime temperatures are likely to be warmer than average for northern and southeastern Australia.
Spring nights are likely to be warmer than average over northern and eastern Australia, though frost risk remains in areas with clear skies and dry soils.
Both of Australia's major climate drivers at this time of year, the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), remain neutral. Secondary climate drivers are likely to be affecting this outlook. These include sea surface temperatures around the Australian coastline, as well as higher pressures to the south of the continent encouraging more easterly flow across Australia.

Spring (September to November) rainfall is likely to be below average for southwest Australia. However, parts of southeast Queensland and far east Gippsland have a slightly increased chance of a wetter than average spring. For most of the country, there are roughly equal chances of a wetter or drier spring.
Both ENSO and the IOD are neutral, resulting in no strong or widespread outlook for wetter or drier conditions.
Higher pressures are favoured south of Australia, meaning greater easterly flow across southern Australia. This would favour increased rainfall on the east coast, and drier conditions in the west.
Historical outlook accuracy for September to November is moderate for most of Australia, but low in northern and western parts of WA. See map for more detail.

Daytime temperatures are likely to be warmer than average for northern and southeastern Australia during spring.
Spring nights are likely to be warmer than average over northern and eastern Australia.
Warmer sea surface temperatures off the northern and eastern coasts are likely to be influencing this outlook, causing overnight temperatures to be warmer than average.
Historical accuracy for maximum temperatures is moderate to high over most of Australia, except for an area surrounding Exmouth in WA. Minimum temperature accuracy is moderate for most of Australia, except western and northern WA, and northern parts of the NT and Queensland where accuracy is low.

Both of Australia's major climate drivers at this time of year, the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), remain neutral.
While Australia's major climate drivers remain neutral, secondary climate drivers are likely to affect Australia. Warmer sea surface temperatures to the north and east of Australia are likely to persist. This combined with drier soils means the north has increased chances of a warmer spring.
The rainfall outlook reflects the neutral climate drivers with no strong widespread likelihood for wetter or drier conditions. However, the increased easterly flow across the south of the country has meant parts of the east coast have slightly increased chances of wetter conditions (more moist onshore flow), while parts of the west are likely to be drier (more drier inland air, and less onshore flow).
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.