Climate outlook for September to December

Issued 29 August 2019

Climate outlook overview

A drier than average end to the year is likely for much of Australia, although the outlook for western Tasmania and southwest WA indicates a wetter than average September.
Spring days are likely to be warmer than average for mainland Australia, but cooler for western Tasmania.
Warmer than average nights are likely in the north and west during spring. With below average rainfall forecast and therefore clearer skies, nights are likely to be cooler than average in parts of the south at times, with increased risk of frost in susceptible areas.
Cooler than average nights are also expected in the tropics in the coming weeks.
A positive Indian Ocean Dipole (IOD) remains the main driver of Australia's climate over the coming months. A positive IOD is typically associated with below average rainfall and warmer than average days for large parts of southern and central Australia.

A drier than average spring is likely for most of Australia, although the outlook for western Tasmania and southwest WA indicates a wetter than average September.
A drier than average October to December is also likely for most of Australia, meaning the remainder of the year is expected to be drier than average for much of the country.
This means little relief is in sight for those currently experiencing rainfall deficiencies after a dry start to the year for large parts of Australia.
A positive Indian Ocean Dipole (IOD) remains the main driver of Australia's climate. A positive IOD is typically associated with below average rainfall for large parts of southern and central Australia in spring.

Spring days are likely to be warmer than average for most of Australia, except Tasmania.
It is likely to be particularly warm during mid-September over parts of central and eastern Australia.
Likewise, October to December is also likely to be warmer than average for Australia except western Tasmania, meaning a warmer than average end to the year is likely.
Warmer than average nights are likely in the north and west during spring, including northern NSW.
Cooler than average nights are likely in the southeast at times during spring, meaning an increased risk of late season frost on cool clear nights in susceptible areas.
In the coming weeks, cooler than average nights are also expected in the tropics.

A positive Indian Ocean Dipole (IOD) is forecast to continue through spring. Typically this means below average rainfall for much of central and southern Australia during winter-spring, which is consistent with the current spring outlook. The positive IOD is likely to be the dominant climate driver for Australia during the next three months.
Pressure patterns over the Tasman Sea are favouring a reduction in onshore flow for parts of the east coast of Australia, and likely contributing to the warmer and drier conditions forecast across NSW and southern Queensland. This pattern is also contributing to the wetter than average outlook for western Tasmania.
The El Niño–Southern Oscillation (ENSO) is expected to remain neutral for the remainder of 2019.
In addition to the natural drivers such as ENSO and the IOD, Australian climate patterns are being influenced by the long-term increasing trend in global air and ocean temperatures.

Product code: IDCKOATCO2