Climate outlook for August to November

Climate outlook overview

  • The next two weeks are likely to see below average rainfall for large parts of Australia. A wetter than average fortnight is likely for much of the east coast of Queensland and coastal NSW.
  • The outlook for August to October indicates a wetter than average three-month period for most of the eastern two thirds of Australia, and the parts of WA. Chances of exceeding median rainfall are roughly equal for southwest WA, southeast SA, Victoria, and western Tasmania.
  • Both days and nights are likely to be warmer than average across Australia during August to October, though chances of warmer or cooler than average days are roughly equal across parts of the southern mainland between northern NSW and southeast WA.
  • The tropical Pacific Ocean is expected to cool and map approach La Niña levels over the coming months. Warmer than average waters are likely in much of the central and eastern Indian Ocean, with both ocean basins influencing a wetter August to October outlook.

Much of Australia drier, but a wetter fortnight likely for the east coast; a wetter 3 months then likely for most of Australia

  • The fortnight of 13 to 26 July is likely to be drier than average for large parts of Australia, stretching from the northwest through Central Australia to Tasmania and the southeast away from the east coast (mostly 65–80% chance). However, much of the east coast of NSW and Queensland have increased chances of a wetter than average fortnight, extending to the northern tropical coast and adjacent inland (greater than 70% chance in many areas).
  • The August to October outlook indicates that most of the eastern two thirds of Australia are likely to see a wetter than average three months, as are parts of WA from the western Pilbara, to the northern South West Land Division, and parts of the inland south (greater than 70% chance over much of SA, NSW, and Queensland). However, chances of a wetter than average season are close to equal for much of southeast SA, Victoria, western and central Tasmania, and southwest WA.
  • The northern Australian dry season spans May through September. Tropical northern Australia typically has very low rainfall totals during the dry season, and only a small amount of rainfall is needed to exceed the median.

Warmer days and nights for most of Australia

  • Daytime temperatures for the next two weeks (13 to 26 July) are likely to be warmer than average for most areas, except parts of Queensland's northern tropics; likely 2–4 degrees warmer than usual for much of northwest and central WA, and up to 2 degrees warmer than average for the remainder of Australia.
  • For 13 to 26 July, nights are likely to be warmer for most of Australia, although chances of warmer or cooler nights are roughly equal for much of the southern NT and inland SA.
  • Days during August to October are very likely to be warmer than average for most of the northern half of Australia (greater than 80% chance for most of the tropics), with a 65–80% chance across much of Victoria, Tasmania, southeast and coastal NSW, and the coastal fringe of WA.
  • Night-time temperatures for August to October are very likely to be warmer than average for Australia (greater than 80% chance in most areas; 65–80% chance for parts of southern WA, 70–80% for southeast SA).

Climate influences

  • The central and eastern tropical Pacific is expected to continue to cool in the coming months, and the majority of models anticipate this cooling will reach or exceed the threshold for La Niña by the end of spring.
  • While waters to the northwest of Australia and in the tropical eastern Indian Ocean are forecast to warm—a typical component of a negative Indian Ocean Dipole (IOD) event—the Bureau's model suggests a neutral IOD is most likely for the coming months. Half of the international models surveyed by the Bureau suggest a negative IOD may develop during spring.
  • A negative IOD typically brings above average winter–spring rainfall to southern Australia, while La Niña favours above average winter–spring rainfall for much of eastern, central, and northern Australia.
  • The Southern Annular Mode (SAM) is expected to remain neutral for the coming fortnight.
  • Australia's temperature and rainfall variability are also influenced by global warming caused by human activities. Australia's climate has warmed by around 1.4 °C since 1910, while southern Australia has seen a reduction of 10–20% in cool season (April–October) rainfall in recent decades.
  • The Bureau's climate model uses the physics of our oceans, ice and land surface combined with millions of observations from satellites and on land and sea. As a result, these outlooks include influences from climate change and natural climate drivers like ENSO, IOD, the MJO, and SAM.

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