Climate outlook for June to September

Long-range forecast overview

• For June to August, below median rainfall is likely to very likely (60% to greater than 80% chance) for virtually all of Australia.
• June to August maximum temperatures are likely to very likely (60% to greater than 80% chance) to be warmer than median for virtually all of Australia.
• Above median June to August minimum temperatures are likely to very likely (60% to greater than 80% chance) for much of Australia, with below median minimum temperatures likely for parts of eastern SA and western NSW.
• This forecast is being influenced by several factors, including likely warming in the tropical Pacific Ocean towards El Niño thresholds, potential development of a positive Indian Ocean Dipole, and record warm oceans globally.

Drier than average June to August for virtually all of Australia

• For June, below median rainfall is likely to very likely (60% to greater than 80% chance) for virtually all of the country.
• For June to August, below median rainfall is likely (60% to 80% chance) for the majority of Australia, increasing to very likely (greater than 80% chance) for some southern areas of the country including southwest WA, southeast parts of SA and NSW, most of Victoria and northern Tasmania. Parts of southern Tasmania and coastal NSW have roughly equal chances of above or below median rainfall while eastern Cape York Peninsula is likely (60% to 80% chance) to exceed median rainfall.
• For June to August, much of Australia is at least twice as likely to receive unusually low rainfall with some parts of southern and north-western Australia more than three times as likely (where unusually dry is amongst the driest 20% of June to August periods over 1981-2018).
• Past accuracy of June to August long-range forecasts for chance of above median rainfall has generally been moderate to high for most of Australia increasing to high to very high for southeast Queensland and inland NSW and Victoria. Accuracy is low for some parts of the northern tropics.

Warmer than average days for virtually all Australia during June to August

• For June, above median maximum temperatures are likely to very likely (60% to greater than 80% chance) for most of the country, excluding some areas of the top third of Australia.
• For June to August, above median maximum temperatures are very likely (greater than 80% chance) for most of Australia, decreasing to likely (60% to 80% chance) for some areas of the northern tropics.
• The southern two-thirds of Australia is at least twice as likely to experience unusually high maximum temperatures during June to August (amongst the warmest 20% of records at this time of the year), with areas of Victoria, SA, NSW and western WA more than four times as likely to experience unusually high maximum temperatures.
• For June, above median minimum temperatures are likely to very likely (60% to greater than 80% chance) for small parts of northeast QLD, southern and eastern coastal areas around the mainland and virtually all of Tasmania. However, for large regions of southern Australia, and the coastal Kimberly there is a likely (60% to 80% chance) of minimum temperatures below median.
• For June to August, minimum temperatures are likely to very likely (60% to greater than 80% chance) to be above median for much of Australia, excluding a region of inland NSW and SA where minimum temperatures are likely (60% to 80% chance) to be below median.
• Past accuracy of the June to August chance of above median maximum temperature long-range forecasts has been moderate to high across most of Australia, excluding a region in the south-east NT extending into western Queensland where accuracy drops to low. For minimum temperatures, accuracy has been moderate to very high, excluding parts of northern and southwest WA and southern SA where accuracy drops to low.

Climate influences

Long-range forecasts reflect several significant climate influences. These include:

• The Pacific Ocean is currently ENSO-neutral and the ENSO Outlook remains at El Niño WATCH. Long-range forecasts currently suggest El Niño development during winter. El Niño increases the chances of below average rainfall for eastern Australia.
• The Indian Ocean Dipole (IOD) is currently neutral. Long range forecasts suggest that a positive IOD event could develop in winter. A positive IOD typically supresses winter and spring rainfall over much of Australia, and if it occurs with El Niño, it can exacerbate the drying effect. IOD forecasts made at this time of year are less reliable beyond June.
• The Southern Annular Mode (SAM) index is currently positive and is expected to return to neutral in the coming days and then remain neutral for the coming fortnight. At this time of the year, SAM has little influence on Australian rainfall patterns. As we head into winter, positive SAM typically reduces rainfall across south-western and south-eastern parts of the continent.
• Sea surface temperatures are forecast to be warmer than average surrounding much of Australia including warm anomalies greater than 0.8°C in the Coral Sea and Tasman Sea, but cool anomalies are forecast for parts of the northern coast of Australia, and off the NSW coast during June 2023.
• For the global sea surface temperature overall, it was the warmest April on record and for the Coral Sea the 2nd warmest April on record.
• Longer-term trends: Australia's climate has warmed by around 1.47 °C in the period 1910–2021, leading to an increase in the frequency of extreme heat events. Southern Australia has seen a reduction of 10 to 20% in cool season (April–October) rainfall in recent decades.

The Bureau's climate model uses the physics of our atmosphere, oceans, ice, and land surface combined with millions of observations from satellites and on land and sea. As a result, it incorporates the influence of climate change and natural climate drivers like ENSO, IOD, the MJO, and SAM in its long-range forecasts.