Climate outlook for August to November 2020
Published Date: 30 Jul 2020
The Bureau of Meteorology has released the climate forecast from August to November 2020.
Climate outlook overview
- The fortnight 3 to 16 August is likely to see above average rainfall across large parts of the interior, extending across SA, NSW and much of Queensland and Victoria.
- The outlook for August to October indicates a wetter than average three-month period for most of the eastern two thirds of Australia, but drier than average for the north-west of WA.
- Both days and nights are likely to be warmer than average across Australia during August to October, though chances of warmer of cooler than average days and nights are roughly equal across much of south-west WA.
- The tropical Pacific Ocean is expected to approach La Niña levels over the coming months, while warmer than average waters are likely in much of the central and eastern Indian Ocean. Both ocean basins are influencing the wetter August to October outlook.
A wetter August to October for much of Australia
- The fortnight of 3 to 16 August is likely to be wetter than average for much of Australia, although chances of a wetter or drier than average fortnight are close to equal across most of the western half of WA, the far northern tropics, and much of Tasmania.
- The August to October period is likely to be wetter than average, with a greater than 65% chance over most of the eastern two thirds of Australia and greater than 75% chance over much of south-west Queensland, south-east NT, western NSW, and inland SA.
- 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 nights for most of Australia, but roughly equal chances in the south-west
- Daytime temperatures for the fortnight 3 to 16 August are likely to be warmer than average for most of northern and eastern Australia, as well as in southwestern WA; up to 2 degrees warmer than usual in the north and east. Elsewhere, temperatures are more likely to be close to average.
- For 3 to 16 August, nights are likely to be warmer for most of Australia; with temperatures 2 to 4 degrees warmer than average over much of northern NSW, Queensland, and the NT.
- Days during August to October are likely to be warmer than average for most of Australia (greater than 80% chance for most of the tropics, Tasmania, much of Victoria and eastern NSW); however, much of the South West Land Division in WA has close to equal chances of warmer or cooler than average days.
- Night-time temperatures for August to October are very likely to be warmer than average for Australia (greater than 80% chance in most areas), although chances are close to equal for much of south-west WA.
Maximum temperature maps
Minimum temperature maps
- The central and eastern tropical Pacific is expected to continue to cool in the coming months. The majority of models anticipate this cooling will reach or exceed the threshold for La Niña by the end of spring. A La Niña WATCH is active.
- While waters to the northwest of Australia and in the tropical eastern Indian Ocean are likely to remain warmer than average—a typical component of a negative Indian Ocean Dipole (IOD)—the Bureau's model suggests a neutral IOD is most likely for the coming months.
- The Southern Annular Mode (SAM) is expected to become positive in early August. A positive SAM during winter can bring drier conditions to the southern reaches of the country including Tasmania, but wetter in northern NSW and southern Queensland.
- 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 rainfall across the cool season months (April–October) in recent decades.
- The Bureau's climate model uses the physics of our oceans, atmosphere, ice and land surface combined with millions of observations from satellites and on land and sea. As a result, these outlooks incorporates influences from climate change and natural climate drivers like ENSO, IOD, the MJO, and SAM.